Pharmacotherapy A Pathophysiologic Approach, 9th Ed.


2,3-Bisphosphoglycerate: An intermediate in the Rapoport-Luebering shunt, formed between 1,3-bisphosphoglycerate and 3-phosphoglycerate; an important regulator of the affinity of hemoglobin for oxygen.

5-α-Reductase: Enzyme responsible for conversion of testosterone to its active metabolite dihydrotesterone. Two types of this enzyme exist. Type 2 is predominant in prostate cells.

α-Amino-3-hydroxy-5-methyl-4 isoxazolepropionate (AMPA)/kainate receptors: Two of three types of ionotropic post-synaptic glutamate receptors. These receptors are similar and are often considered together. Upon binding glutamate, these receptors permit the influx of Na+ ions and result in brain excitation. These are one of the two primary receptors for excitatory neurotransmission in the brain.

α-Amino-3-hydroxy-5-methylisoxazole-4-propionate: See AMPA.

α-Hydroxy acids: Exfoliating products such as lactic, glycolic, malic, mandelic, and tartaric acid used in cosmetics.

β-Hydroxy acid: Salicylic acid.

γ-Aminobutyric acid (GABA): The major inhibitory neurotransmitter in the central nervous system.

γ-Aminobutyric acid (GABAA) receptors: Postsynaptic ionotropic receptors that bind to GABA and result in Cl influx and neuronal hyperpolarization. GABA is the main inhibitory neurotrasmitter in the brain and GABAAreceptors mediate fast CNS inhibitory neurotransmission.

Abscess: A purulent collection of fluid separated from surrounding tissue by a wall comprised of inflammatory cells and adjacent organs. It usually contains necrotic debris, bacteria, and inflammatory cells.

Abstinence: Refraining from the indulgence in something, as sexual intercourse or substances, by one’s own choice. The absence of genital contact that could permit a pregnancy (i.e., penile penetration into the vagina).

Acanthosis: Increased thickness of the prickle cell layer of the skin.

Acculturation: The process by which individuals from one cultural group adopt or change behaviors, attitudes, and/or beliefs through contact with a different culture.

Acetabular: Relating to the acetabulum, the hollow, cuplike portion of the pelvis into which the head of the thigh bone (femur) fits.

Achalasia: Problem that occurs when a ring of muscle fibers, such as a sphincter of the esophagus, fail to relax.

Acne: Inflammatory eruption of the sebaceous gland.

Acnegenicity: Product effect that causes irritation of follicles resulting in papules and pustules.

Acquired resistance: See Secondary resistance.

Acromegaly: A pathologic condition characterized by excessive production of growth hormone.

Activities of daily living: Dressing, bathing, getting around inside the home, feeding, toileting, and grooming. See also Instrumental activities of daily living.

Acute bacterial pharyngitis: Acute bacterial infection of the oropharynx or nasopharynx.

Acute bacterial sinusitis: Acute bacterial infection of the paranasal sinuses lasting less than 30 days.

Acute coronary syndrome (ACS): Ischemic chest discomfort at rest most often accompanied by ST-segment elevation, ST-segment depression, or T-wave inversion on the 12-lead electrocardiogram; further, it is caused by plaque rupture and partial or complete occlusion of the coronary artery by thrombus. Acute coronary syndromes include myocardial infarction and unstable angina. Former terms used to describe types of ACS include Q-wave myocardial infarction, non–Q-wave myocardial infarction, and unstable angina.

Acute kidney injury (AKI): Abrupt decrease in kidney function resulting in an increase in serum creatinine and/or decrease in urine output. AKI is usually classified as prerenal, instrinsic, or postrenal type.

Acute otitis media: Acute inflammation of the middle ear.

Acute pain: Can be a useful physiologic process warning individuals of disease states and potentially harmful situations. Severe, unremitting, undertreated, acute pain, when it outlives its biologic usefulness, can produce many deleterious effects (e.g., psychological problems). It usually subsides when the healing process decreases the pain-producing stimuli.

Acute pancreatitis: Acute inflammation of the pancreas that can be mild with minimal or no organ dysfunction or severe with organ failure and local complications.

Acute stress disorder: A disorder characterized by anxiety, dissociative, and other symptoms that occurs within 1 month after exposure to an extreme traumatic stressor.

Adaptive functioning: Individual effectiveness coping with everyday stressors compared to a peer with similar background, and socioeconomic and psychosocial opportunities.

Adaptive inflammation: Inflammatory pain that promotes the shifting from prevention of tissue damage to promotion of healing.

Addiction: A primary, chronic, neurobiologic disease, with genetic, psychosocial, and environmental factors influencing its development and manifestations. It is characterized by behaviors that include one or more of the following five Cs: chronicity, impaired control over drug use, compulsive use, continued use despite harm, and craving.

Adjuvant analgesics: Agents that are useful in the treatment of pain but are usually not classified as analgesics.

Adjuvant therapy: Any therapy administered after primary surgical resection of the tumor or cancer, with the intent to eradicate micrometastes and cure the disease.

Administrative burden: The demands placed on those who administer an instrument.

Adolescents: Pediatric patients who are 12 to 16 years of age.

Adoptive immunotherapy: Administration of immune cells for the treatment of cancer.

Adrenergic: Neuronal or neurologic activity caused by neurotransmitters such as epinephrine, norepinephrine, and dopamine.

Adrenocorticotropic hormone (ACTH): A polypeptide hormone secreted by the anterior pituitary that controls secretion of cortisol from the adrenal glands.

Adverse drug events: Injuries resulting from administration of a drug or other circumstances surrounding use of the drug but not necessarily caused by the drug itself. See also Adverse drug reaction.

Adverse drug reaction: Any noxious, unintended, and undesired effect of a drug that occurs at doses used in humans for prophylaxis, diagnosis, or therapy.

Aerophagia: Excessive swallowing of air.

Affect: Pattern of behaviors that a clinician can observe that expresses a person’s current state of emotion.

Afterload: The pressure or the “load” the heart must generate to eject blood into the systemic circulation. Although approximated by the systemic vascular resistance, it is a complex measure that includes blood viscosity, aortic impedance, and ventricular wall thickness. Along with preload, it is an important determinant of cardiac output.

Aganglionosis: The state of being without ganglia.

Agnosia: Cardinal symptom of Alzheimer’s disease; inability to recognize or identify a familiar object in the absence of impaired sensory function.

Agoraphobia: Anxiety about, or avoidance of, places or situations from which escape might be difficult (or embarrassing) or in which help might not be available in the event of having a panic attack or panic-like symptoms.

Akathisia: The sensation of inner restlessness resulting in the need to make movements such as pacing or moving the legs. Akathisia has subjective and objective components.

Albumin: The major protein in plasma, with a molecular weight of 65 kDa.

Albuminuria: A condition where a large amount of albumin (>300 mg/day) is present in the urine, often indicating glomerular damage in the kidney.

Alcohol ablation: Alcohol ablation of the septum is a nonsurgical procedure to improve outflow tract obstruction. It is a percutaneous catheter-based method to decrease septal thickness by therapeutic myocardial infarction.

Alcoholism: A chronic, progressive, and potentially fatal biogenic and psychosocial disease characterized by tolerance and physical dependence and manifested by a total loss of control, as well as diverse personality changes and social consequences.

Algorithm (treatment algorithm): Identifies and specifies sequences for treatment alternatives, with specific options and tactics for care. Based on scientific data and on expert consensus in areas where there are little scientific data, algorithms are divided into stages so that the simplest, most efficacious, and best-tolerated treatments available are tried first. If results are not optimal, treatment advances to the next stage. Unless a patient’s illness fails to improve sufficiently with early-stage treatments, he or she is spared treatments that are more complex, that might be less well tolerated, or that have more potential for drug interactions or serious side effects. Algorithms recommend key decision points in treatment decision making.

Allergic interstitial nephritis: Inflammation of the interstitial region of the kidney often associated with acute onset of renal insufficiency.

Allergic salute: Constant upward rubbing of the nose as a result of allergies.

Allergic shiners: Dark circles under the eyes as a result of nasal congestion leading to venous pooling.

Allodynia: Painful response to normally non-noxious stimuli.

Allogeneic transplantation: Transfer of cells between genetically nonidentical individuals.

Allograft: An organ or tissue transplant from one human being to another.

Allokinesis: A phenomenon whereby pruritic skin affects the surrounding normally nonpruritic skin area, whether inflamed or noninflamed. The nonpruritic skin becomes very sensitive, reacts to light stimuli, and begins itching.

Alloimmunization: Rapid consumption of transfused platelets through an immune-mediated reaction.

Alternate forms: All modes of administration other than the mode for which the instrument was originally developed.

Amenorrhea: Lack of menstruation or the abnormal ending of the female menstrual cycle.

American Urological Association (AUA) Symptom Index: A validated questionnaire of seven questions that can be used by patients to assess the bothersomeness of their voiding symptoms. The total score range is 0 to 35. Higher scores are consistent with severely bothersome symptoms.

Amnesia: A pathologic impairment of memory.

AMPA/kainate receptors: Two of three types of ionotropic postsynaptic glutamate receptors. These receptors are similar and are often considered together. On binding glutamate, these receptors permit the influx of sodium ions (Na+) and results in brain excitation. These are one of the two primary receptors for excitatory neurotransmission in the brain.

Amygdala: A small almond-shaped temporal lobe structure that plays a role in emotions and fear control.

Anaphylactoid: Anaphylaxis-like reactions that do not involve immunoglobulin E (IgE)-mediated mechanisms.

Anaphylaxis: Acute, life-threatening allergic reaction involving multiple organ systems.

Anastomosis: The surgical connection of two tubular structures, such as blood vessels, in a transplanted organ.

Andropause: Refers to a number of symptoms associated with decreased testosterone production by the testes in aging men. The symptoms include decreased libido, increased body fat, depressed mood, and osteoporosis. The symptoms of andropause generally worsen as the patient ages. Andropause in men parallels menopause in women.

Anemia of chronic disease: Mild-to-moderate anemia not associated with blood loss or hemolysis. Usually with normal cell size. Can be seen with chronic inflammation (e.g., rheumatoid arthritis, chronic infection) or malignancy.

Anemia of chronic kidney disease: A decrease in red blood cell production caused by a deficiency in the hormone erythropoietin normally produced by progenitor cells of the kidney. As kidney function declines, less erythropoietin is available to stimulate red blood cell production (erythropoiesis) in the bone marrow. Contributing factors include iron deficiency and a shortened, red blood cell life span.

Aneuploid: Deviation by a whole number in the total number of chromosomes in a cell compared to normal (46 in humans).

Angioedema: An allergic reaction characterized by edema of a tissue such as the lips, eyes, mouth, joints, or other structures because of leak of fluid from blood vessels.

Anhedonia: A lack of pleasure or interest in usual activities.

Anisocytosis: Considerable variation in the size of cells that are normally uniform, especially with reference to red blood cells.

Ankylosis: Bony fusion resulting from chronic joint inflammation.

Anomia: Cardinal symptom of Alzheimer’s disease; inability to name objects or to recognize names.

Anorexia nervosa: A psychiatric disorder in which patients present with a fear of being obese. These patients often express a dislike or lack of interest in food; it is most common in young females and can disrupt normal menstrual cycles. It is associated with poor medication treatment response and can result in fatal medical complications.

Anosognosia: Lack of self-awareness or ignorance, real or feigned, of the presence of disease.

Antenatal: Time between conception and birth; same as prenatal.

Anterograde amnesia: Inability to remember events or actions that occur after taking a sedative hypnotic medication.

Antibiogram: A summary of antimicrobial susceptibilities.

Anticipatory anxiety: The fear of having an anxiety attack, which is often a trigger by itself; “fear of fear.”

Anticoagulant: Any substance that inhibits, suppresses, or delays the formation of blood clots. These substances occur naturally and regulate the clotting cascade. Several anticoagulants have been identified in a variety of animal tissues and have been commercially developed for medicinal use.

Antigenic drift: The creation of antigenic variants by point mutations in the surface antigens, hemagglutinin and/or neuraminidase, of a particular subtype of influenza.

Antigenic shift: Occurs when an influenza virus acquires a new hemagglutinin and/or neuraminidase.

Antimicrobial cycling: A predetermined change in an antimicrobial recommendation for empiric therapy of a specific infection at a predetermined time.

Antimycotic: Inhibiting fungal growth.

Antithrombotic: A pharmacologic agent that prevents thrombus/clot formation. This category includes both antiplatelet agents and anticoagulants.

Anuria: Production of less than 50 mL of urine/day.

Anxiety: A state of apprehension, uncertainty, and fear resulting from the anticipation of a realistic or fantasized threatening event or situation that often impairs physical and psychological functioning.

Aortic stenosis: Aortic stenosis is the obstruction of blood flow across the aortic valve. This disorder has several etiologies: congenital unicuspid or bicuspid valve, rheumatic fever, and degenerative calcific changes of the valve.

Aphasia: Cardinal symptom of Alzheimer’s disease; inability to generate or comprehend spoken language.

Aphthous ulcer: A small superficial area of ulceration within the gastrointestinal mucosa, typically found in the oral cavity.

Apical pulse: Point at the apex (bottom portion) of the heart impacts the chest wall.

Apoptosis: Programmed cell death.

Appendageal: Referring to hair, sweat glands, and nails.

Apraxia: Cardinal symptom of Alzheimer’s disease; inability to carry out a motor task in the absence of impaired motor function.

Aromatase: Enzyme responsible for conversion of estrogens (estradiol and estrone) to androgens (androstenedione and testosterone).

Arteriovenous (AV) fistula: In hemodialysis, a vascular access surgically created by connection of an artery directly to a vein, usually in the forearm.

Arteriovenous (AV) graft: In hemodialysis, a vascular access surgically created using a synthetic tube to connect an artery to a vein.

Arteriovenous malformations: A tangle of blood vessels, both arterial and venous, that can rupture and cause hemorrhage in the brain.

Arthrodesis: The surgical immobilization of a joint (i.e., joint fusion).

Arthropathy: Disease of the joints.

Ascites: Accumulation of serous fluid in the peritoneal cavity.

Asherman’s syndrome: A cause for menstrual flow obstruction; often resulting from infection or surgery affecting the endometrium.

Asperger’s disorder: A type of pervasive developmental disorder characterized by severe and sustained impairment in social interaction, restricted and repetitive patterns of behavioral/interested activities—similar to autism but without clinically significant delays in language and cognitive development or age-appropriate self-help skills.

Aspiration pneumonitis: The inflammation of lung tissue caused by the aspiration of fluids and gastric contents that often leads to dyspnea, pulmonary edema, secondary infections, and adult respiratory distress syndrome. Hydrocarbon pneumonitis is caused by the pulmonary aspiration of hydrocarbons such as kerosene and gasoline.

Assertive community treatment: A treatment program for the care of individuals with schizophrenia in which teams provide comprehensive wraparound services for the patient, including going to the home to provide support for daily living skills, housing, and supported employment. Team members are available 24 hours daily if needed to meet the patient’s comprehensive care needs.

Asystole: The presence of a flat line on the electrocardiogram monitor.

Ataxia: Loss of the ability to coordinate muscular movement.

Atelectasis: Pulmonary parenchymal collapse caused by alveolar or bronchial obstruction.

Atopic dermatitis: Skin inflammation that causes itching, scales, and erythema.

Atopic pleat (Dennie–Morgan fold): An extra fold of skin that develops under the eye, characteristic of atopic dermatitis.

Atopy: An allergic syndrome characterized by asthma, hay fever, and urticaria or eczema.

Atrial fibrillation: Rapid beating of the atria that results in variable ventricular rates.

Atropinism: Symptoms of poisoning by atropine or belladonna.

Aura: Sensory or somatosensory alteration without loss of consciousness.

Augmentation: Addition of a medication not usually used as monotherapy for a disorder to a core medication for a disorder in an attempt to enhance the patient’s clinical response.

Auscultation: Listening to the heart or other organs with a stethoscope.

Autism/Autistic disorder: A type of pervasive developmental disorder with a neurobiologic etiology, characterized by impaired reciprocal social interaction, impaired communication skills, and a limited range of activities and interests; frequently associated with mental retardation; sometimes referred to as early infantile autism, childhood autism, or Kanner autism.

Autologous transplantation: Readministration of the same person’s cells that were previously collected.

Autosomal: Pertaining to a chromosome.

Axonal transaction: Destroying or severing the axon so that electrical impulses are impeded along the nerve sheath or across the nerve synapse. Axonal damage is not reversible and leads to long-term disability and the formation of black holes.

Azotemia: Term referring to elevated levels of urea in the serum or blood.

Azotorrhea: An excessive loss of protein in the feces.

Bacteremia: Presence of viable bacteria (fungi) in the bloodstream.

Bacterial prostatitis: An inflammation of the prostate gland and surrounding tissue as a result of infection.

Bacteriuria: The presence of bacteria in the urine.

Barrett esophagus: Inflammatory changes in the esophagus resulting in replacement of epithelial lining by columnar-type cells that can lead to stricture or adenocarcinoma.

Basal ganglia and striatum: Parts of the brain regulating movements.

Behavioral phenotype: The actions or reactions of a person to internal or external environmental influences.

Benign prostatic hyperplasia: Nonmalignant enlargement of the prostate gland in elderly men.

Bilateral salpingo-oophorectomy: Surgical excision (removal) of both ovaries.

Biliverdin: A green bile pigment formed from the oxidation of heme.

Binge eating: Excessive intake of calorie-laden food over a short period of time.

Bioavailability: The fraction of drug absorbed into the systemic circulation after extravascular administration.

Biochemical markers: Intracellular macromolecules released into the peripheral circulation from necrotic myocytes as a result of myocardial cell death (infarction). These laboratory tests are used in the diagnosis of myocardial infarction. Examples include troponin I, troponin T, creatinine kinase myocardial band (MB), and myoglobin.

Biofilm: A population or community of microorganisms adhering to a surface by a secreted coating. This coating also reduces microorganism vulnerability to antibiotics.

Biopsy: A procedure in which a tiny piece of a body part, such as the kidney or bladder, is removed for examination under a microscope.

Bioterrorism agents: Organisms or toxins that can cause disease and death in humans, animals, or plants for the purpose of eliciting terror.

Bipolar I disorder: Characterized by one or more manic episodes. The manic episode may have been preceded by and may be followed by hypomanic or major depressive episodes.

Bipolar II disorder: Characterized by at least one hypomanic episode and at least one major depressive episode.

Bleeding diathesis: A condition in which there is an unusual susceptibility or predisposition to bleeding.

Blood urea nitrogen (BUN): A waste product in the blood that comes from the breakdown of food protein. The kidneys filter blood to remove urea and thus maintain homeostasis. As kidney function decreases, the BUN level increases.

Blood–brain barrier: The relative lack of permeability of large molecules (and those molecules lacking lipid solubility) into the central nervous system because of the nonfenestrated capillary beds of the cerebral vasculature.

Borborygmi: Rumbling or gurgling noises produced by movement of gas, fluid, or both in the alimentary canal and audible at a distance.

Brachytherapy: A procedure in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into or near a tumor. Also called internal radiation, implant radiation, or interstitial radiation therapy.

Bradykinesia: Delay or slowness in initiating and performing purposeful, voluntary movement as seen in Parkinsonism.

Breakthrough bleeding: The unpredictable and irregular bleeding associated with hormone therapy.

Bronchiectasis: Dilation of a bronchus or bronchi, usually related to excessive secretions.

Bronchioles: A subdivision of bronchi; smaller in diameter and without cartilage.

Bronchiolitis: Inflammation of the bronchioles.

Bronchoalveolar lavage: Instilling and then removing a lavage fluid to reveal the secretory and/or cellular contents from deep in the lung.

Bronchorrhea: Excessive bronchial secretions that can impair pulmonary ventilation.

Bruit: An abnormal and often harsh sound heard over a blood vessel, usually an artery, on examination with a stethoscope caused by turbulent blood flow.

B-type natriuretic peptide: B-type natriuretic peptide is a 32-amino-acid polypeptide secreted by the ventricles in response to excessive myocyte stretching. Elevated levels are typically seen in patients with left ventricular dysfunction and can correlate with both the heart failure severity and the prognosis.

Bulimia nervosa: A psychiatric disorder manifested by episodes of consuming a large caloric load over a short period of time (binge eating), with subsequent self-induced vomiting, use of cathartics or diuretics, fasting, or excessive exercise to prevent weight gain.

BUN (blood urea nitrogen): A waste product in the blood that comes from the breakdown of food protein. The kidneys filter blood to remove urea. As kidney function decreases, the BUN level increases.

Bursitis: Inflammation of the bursa, a fluid-filled soft tissue structure that usually results in pain and swelling.

Caffeinism: A clinical syndrome produced by acute or chronic overuse of caffeine characterized by anxiety, psychomotor alterations, sleep disturbances, mood changes, and psychophysiologic complaints.

Calcimimetic: A class of agents that stimulate calcium-sensing receptors on the parathyroid gland and mimic the effects of extracellular calcium. They suppress parathyroid hormone (PTH) release and increase the sensitivity of the receptor to extracellular calcium.

Calcium-sensing receptor: The calcium receptor on the chief cells of the parathyroid gland, activation of which leads to suppression of PTH release.

Candidiasis: Fungal infection involving Candida species.

Carbuncles: Broad, swollen, erythematous, deep, and painful, follicular masses commonly associated with fever, chills, and malaise.

Carcinoid: A carcinoid is a slow-growing tumor usually located in the gastrointestinal system and sometimes in the lungs or other sites. Carcinoids can spread to the liver and can secrete serotonin or prostaglandins.

Cardiac arrest: The sudden cessation of cardiac mechanical activity as confirmed by the absence of signs of circulation.

Cardiac index: Cardiac output standardized for body surface area. Mathematically, cardiac index = cardiac output/body surface area.

Cardiac output: The volume of blood pumped by the heart per unit of time. Cardiac output is the product of heart rate and stroke volume.

Cardioembolic stroke: An ischemic stroke thought to be caused by an embolism arising from the heart. Cardioembolic stroke can be assumed in patients with significant cardiovascular disease including atrial fibrillation, dilated cardiomyopathy, prosthetic valves, recent myocardial infarction (MI), and patent foramen ovale.

Cardiopulmonary bypass: The use of extracorporeal devices to pump blood and oxygenate the blood while the heart or lungs are not functional. Extracorporeal membrane oxygenation (ECMO) is a form of long-term cardiopulmonary bypass that is typically used for days to weeks.

Cardiopulmonary resuscitation: The attempt to restore spontaneous circulation by performing chest compressions with or without ventilations.

Carotid Doppler: A technique that provides information about the presence and severity of atherosclerosis of the carotid artery using noninvasive sound wave technology.

Carotid endarterectomy: Removal of the atherosclerotic plaque from the inside of a stenotic carotid artery by a surgical technique. The vessel is surgically opened and sewn and/or patched after removal of the plaque.

Carpal tunnel syndrome: A medical condition in which the median nerve is compressed at the wrist, leading to parethesias, numbness, and muscle weakness in the hand.

Case-control study: An observational study of persons with the disease of interest (cases) and a suitable control group of persons without the disease to establish the extent of association between exposure(s) of interest and disease.

Castration: Removal of the ovaries or testicles.

Cataplexy: A sudden loss of muscle control with retention of clear consciousness that follows a strong emotional stimulus (e.g., elation, surprise, or anger) and is a characteristic symptom of narcolepsy.

Catheter lock therapy: A method for preventing or treating catheter-related bloodstream infections by instilling a highly concentrated antimicrobial solution into a catheter lumen and allowing the solution to dwell for a specified time period for the purpose of sterilizing the lumen.

Cellulitis: An acute, infectious process that initially affects the epidermis and dermis and can subsequently spread within the superficial fascia.

Central parenteral nutrition: Parenteral nutrition delivered into a large-diameter vein, usually the superior vena cava adjacent to the right atrium.

Central venous catheter: A venous access device inserted percutaneously, or tunneled beneath the skin and terminating in a central vein such as the subclavian, internal jugular, or femoral veins.

Centrilobular: Affecting the central portion of the lobe.

Cerebral autoregulation: The process by which cerebral blood flow is maintained in a tight range over a wide range of peripheral blood pressures. It is accomplished by reactive dilation and constriction of cerebral arteries.

Cerebral blood flow (CBF): The volume of blood perfusing a given brain mass as a function of time.

Cerebral blood volume (CBV): The total volume of blood within the cerebral vasculature at a given point in time.

Cerebral microdialysis: A sampling method that allows continuous acquisition of a small volume of cerebral extracellular fluid specimens using a microdialysis probe inserted into the brain.

Cerebral oxygen consumption (CMRo2): The cerebral metabolic rate for oxygen consumption calculated as the mean hemispheric CBF and the arteriovenous oxygen content difference (AVDo2).

Cerebral oxygen delivery (CDo2): The product of CBF and arterial oxygen content.

Cerebral perfusion pressure: A critical monitoring parameter in traumatic brain injury patients defined as the difference between the mean arterial pressure and the intracranial pressure.

Cerebrospinal fluid: The clear, colorless fluid that bathes and cushions the brain and spinal cord.

Cervical cap: A thimble-shaped latex rubber device that is held on the cervix by suction, thus acting as a barrier to reduce the risk of pregnancy.

Cervical effacement: During the first stage of labor, as the cervix is opening, it is also thinning. The thinning of the cervix is termed effacement.

Cervical ripening: Prior to inducing labor, the cervix must be favorable, approximately 2 cm dilated and 80% thinned out. If this is not the case, an agent must be used to induce histochemical changes to make the cervix more favorable.

Cervical stenosis: A cause for menstrual flow obstruction; often caused by surgical interventions for cervical dysplasia.

Cervicitis: Inflammation of the cervix.

Chancre: A sore or ulcer, the dermal lesion of primary syphilis.

Chancroid: A venereal dermal lesion caused by agents other than syphilis.

Cheilitis: Inflammation of the lips; can be related to retinoid use.

Children: Pediatric patients who are 1 to 11 years of age.

Cholelithiasis: A solid formation in the gallbladder or bile duct composed of cholesterol and bile salts. Also known as gallstone.

Cholestatic hepatitis: Rare form of hepatitis marked by stopped or suppressed flow of bile; characterized by pruritus, dark urine, light-colored stools, elevated alkaline phosphatase, and conjugated bilirubin.

Cholinesterase inhibitors: Class of medication that inhibits enzymatic activity of acetylcholinesterase, butyrylcholinesterase, or both to prevent the degradation of acetylcholine.

Chronic condition: An illness or impairment that cannot be cured.

Chronic kidney disease (CKD): Slow and progressive loss of kidney function that takes several years, often resulting in permanent kidney failure requiring dialysis or transplantation.

Chronic pain/persistent pain: Pain persisting for months to years.

Chronic pancreatitis: Chronic inflammation of the pancreas caused by the many sequelae of long-standing pancreatic injury leading to irreversible pancreatic damage.

Chvostek’s sign: A facial twitch produced by tapping on the cheek over the branches of the facial nerve.

Circumstantial speech: Speech pattern whereby the expressed ideas are characterized by unnecessary detail. The speaker ultimately makes their point, but in a very roundabout manner.

Clearance: The volume of blood per unit time (e.g., L/h, mL/min) completely cleared of a drug.

Clinical inertia: A clinical situation in which no therapeutic move was made to treat a medical condition in a patient that is not considered adequately treated, or at their treatment goal.

Clinical outcomes: Medical events that occur as a result of the condition or its treatment.

Clinical pharmacokinetics: The discipline that describes the absorption, distribution, metabolism, and elimination of drugs in patients.

Clinical proteinuria: Total protein in the urine in amounts greater than 300 mg/day.

Clinical resistance: Refers to failure of an antifungal agent in the treatment of a fungal infection that arises from factors other than microbial resistance, such as failure of the antifungal agent to reach the site of infection, or inability of a patient’s immune system to eradicate a fungus whose growth is retarded by an antifungal agent; applicable to many other drugs.

Clinically isolated syndrome: The first attack of multiple sclerosis characterized by a neurologic syndrome such as optic neuritis and generally seen with silent or asymptomatic white matter lesions (seen on magnetic resonance imaging) suggestive of demyelination. Individuals that experience a clinically isolated syndrome are at high risk of developing definite multiple sclerosis.

Clotting cascade: A series of enzymatic reactions by clotting factors leading to the formation of a blood clot. The clotting cascade is initiated by several thrombogenic substances. Each reaction in the cascade is triggered by the preceding one, and the effect is amplified by positive feedback loops.

Clotting factor: Plasma proteins found in the blood that are essential to the formation of blood clots. Clotting factors circulate in inactive forms but are activated by their predecessor in the clotting cascade or a thrombogenic substance. Each clotting factor is designated by a Roman numeral (e.g., factor VII) and by the letter “a” when activated (e.g., factor VIIa).

Cluster headache: A primary headache disorder characterized by attacks of severe unilateral headache that occurs in series of weeks or months (cluster periods) separated by remission periods usually lasting months or years.

Cluster period: The time during which cluster-headache attacks occur regularly and at least once every other day.

Codon: A sequence of three consecutive nucleotides that specify an amino acid or amino acid chain termination.

Coelomic metaplasia: Transformation of normal cells into endometrial cells.

Cognitive behavioral therapy: A form of psychotherapy designed to replace distorted or inappropriate ways of thinking with healthy, more realistic thoughts to alter maladaptive moods and behavior. It is instructional in approach and is based on the theory that thoughts (not external influences such as people, situations, and events) cause feelings and behaviors. Patients learn to identify the thinking that causes the negative feelings and behaviors and then learn how to replace that thinking with thoughts that lead to more desirable feelings and behaviors.

Cogwheeling: A ratchet-like movement in the joints, characteristic of Parkinson disease.

Cohort study: Assembly of a group of persons without a disease(s) of interest at the onset of the study, determination of the exposure status of each person, and observation of the cohort over time to determine the development of disease in exposed and nonexposed persons.

Colectomy: Surgical removal of the colon.

Colonization resistance: Preservation of anaerobic flora by selective gut decontamination to prevent colonization by potentially pathogenic gram-negative organisms.

Colony-stimulating factors: Proteins that regulate the proliferation, maturation, and differentiation of stem cells to red blood cells, white blood cells, or platelets; may be classified into myeloid growth factors, erythropoietic agents, and thrombopoietic agents.

Coma: A state of unconsciousness whereby a patient is not opening his or her eyes, not obeying commands, and not uttering understandable words.

Comedo, comedones (pl.): Plug of sebum and keratinous material in a hair follicle; blackhead.

Comedogenicity: Product effect that causes follicular plugging resulting in comedones.

Comedolytic: Prevents shed keratinocytes from aggregating in follicle and clogging pores.

Communities: Organized groups of people with a shared identity or relationship that may be based on history, culture, context, or geography.

Comorbidity: A concomitant but unrelated pathologic or disease process.

Complementary and alternative medicine (CAM): Any practice for the prevention and treatment of disease that is not usual conventional medicine.

Complex partial seizure: A seizure beginning in one hemisphere of the brain. It is manifested by automatisms, periods of memory loss, or aberrations of behavior.

Compulsion: Repetitive ritualistic behavior such as ordering or hand washing or a mental act such as repeating words silently with the intent of preventing or reducing distress or some dreaded event or situation.

Conceptual model: The rationale for and description of the concepts that a measurement instrument is intended to assess and the interrelationships of those concepts.

Condom: A sheath, usually made of thin rubber, used to cover the penis during sexual intercourse to prevent conception or infection.

Confounding: A situation in which the effects of two processes are not separated. The distortion of the apparent effect of an exposure on risk brought about by the association of other factors that can influence the outcome.

Constrictive pericarditis: Constrictive pericarditis is a disorder caused by inflammation of the pericardium with subsequent thickening, scarring, and contracture of the pericardium. The pericardium cannot stretch during contraction, thereby preventing chamber filling.

Construct validity: The strength of the relationship between measures purporting to measure or reflect the same underlying theoretical construct.

Content validity: Refers to how adequately the questions/items capture the relevant aspects of the domain or concept being measured.

Continuation therapy: The second phase in drug therapy during which the goal is to eliminate any remaining symptoms and prevent a relapse.

Continuous-combined estrogen-progestogen therapy: Daily administration of both estrogen and a progestogen.

Continuous long-cycle estrogen-progestogen therapy: Estrogen is given daily and a progestogen is given six times a year (every other month for 12 to 14 days).

Contralateral: Of or pertaining to the opposite side of the body.

Convection: The movement of solutes, or metabolic waste products, by bulk flow in association with fluid removal. Convective clearance is not dependent on concentration gradients, and the magnitude of its contribution to total clearance is directly related to the ultrafiltration (fluid removal) rate.

Convulsion: Specific seizure type where the seizure is manifested by involuntary muscle contractions.

Cor pulmonale: Right-sided heart failure caused by lung disease.

Corneocytes: Flattened, dead, keratin-filled epidermal cells.

Coronary artery bypass graft (CABG) surgery: Thoracic surgery where parts of a saphenous vein from a leg or internal mammary artery from the axilla (armpit) are placed as conduits to restore blood flow between the aorta and one or more coronary arteries to “bypass” the coronary artery stenosis (occlusion).

Corpus cavernosum: Two chambers on the dorsal side of the penis. Chambers composed of sinusoidal tissue, which can fill with arterial blood to produce an erection.

Corpus luteum: The small yellow endocrine structure that develops within a ruptured ovarian follicle and secretes progesterone and estrogen.

Corpus spongiosum: One chamber on the ventral side of the penis. Chamber is composed of sinusoidal tissue, which can fill with arterial blood to produce an erection. The urethra passes through the corpus spongiosum.

Cortical necrosis: Acute renal failure secondary to ischemic necrosis of the renal cortex usually caused by significantly diminished renal arterial perfusion.

Corticotropin-releasing hormone (CRH): A trophic hormone released by the hypothalamus that stimulates release of adrenocorticotropic hormone (ACTH).

Cost-effectiveness ratio: The outcome of cost-effective analysis. The numerator of the ratio summarizes the costs and financial savings associated with the therapy, including the costs of the therapy itself, side effects, medical costs, and savings from avoided illness and disability. The denominator of the cost-effectiveness ratio reflects the health effect of the intervention. The year of life saved is probably the most commonly used measure of the health effect.

Cranial nerve palsy: Paralysis of one or more of the 12 cranial (brain) nerves.

Craniectomy (for stroke): Removal of part of the skull overlying an area of injury to relieve the pressure of cerebral edema.

C-reactive protein: An endogenous marker released by the body in response to inflammation.

Creatine kinase, creatine kinase myocardial band: Creatine kinase (CK) enzymes are found in many isoforms, with varying concentrations depending on the type of tissue. Creatine kinase is a general term used to describe the nonspecific total release of all types of CK, including that found in skeletal muscle (MM), brain (BB), and heart (MB). Creatine kinase–MB is released into the blood from necrotic myocytes in response to infarction and is a useful laboratory test for diagnosing myocardial infarction. If the total CK is elevated, then the relative index (RI), or fraction of the total that is composed of CK-MB, is calculated as follows:


A RI greater than 2 is typically diagnostic of infarction.

Creatinine (serum): A protein metabolic by-product obtained from the diet or generated from muscles of the body. Creatinine is removed from blood by the kidneys; as kidney disease progresses, the level of creatinine in the blood increases.

Creatinine clearance: A test that measures how efficiently the kidneys filter creatinine and other waste products from the blood. Low creatinine clearance (<60 mL/min) usually indicates the presence of kidney damage.

Crepitus: A crinkly, crackling, or grating feeling or sound in the joints, skin, or lungs.

Cronbach α-coefficient: Commonly used statistical measure to quantify internal consistency reliability for multi-item scales or tests.

Crossmatch: A test to determine if a recipient has antibodies against donor antigens. A positive crossmatch indicates that the recipient has antibodies against the donor, and the two are incompatible. A negative crossmatch means the recipient does not have antibodies against the donor, and the two are considered compatible.

Crust: Dried exudate, secretion, or hemorrhage; scab.

Crypt abscess: Neutrophilic infiltration of the intestinal glands (Crypts of Lieberkuhn); a characteristic finding for patients with UC.

Cultural competency: The attitudes, knowledge, skills, and values that an individual and/or an organization acquires, develops, and uses to work effectively in a cross-cultural environment.

Culture: The acquired and shared attitudes, beliefs, knowledge, and values that individuals and/or groups use to influence their actions and behavior.

Culture negative endocarditis: Describes a patient in whom a clinical diagnosis of infective endocarditis is likely, but blood cultures do not yield a pathogen.

Cutaneous: Pertaining to the skin.

Cutis: Skin.

Cyanopsia: A condition when a patient sees a blue halo around objects, or objects appear to be blue-colored.

Cyanosis: Bluish tint to the skin or mucous membranes because of lack of oxygen.

Cyclic estrogen-progestogen therapy: Estrogen is taken continuously, with a progestogen added cyclically the last 10 to 14 days during each 28-day cycle.

Cyst: Sac or closed cavity containing fluid, semifluid, or solid material.

Cystitis: Inflammation of the bladder, usually caused by infection.

Cytokines: Protein molecules that are released by one cell (e.g., T-lymphocytes) that can have an influence on other cells. These proteins are important in numerous cell functions, such as regulating the immune response and cell-to-cell communication.

Dactylitis: Erythema and swollen hands, feet, fingers, and toes. Also known as hand-and-foot syndrome.

Deep vein thrombosis: A disorder of thrombus formation causing obstruction of a deep vein in the leg, pelvis, or abdomen.

Defibrillation: The therapeutic use of electric current in attempt to completely depolarize the myocardium and provide an opportunity for the natural pacemaker centers of the heart to resume normal activity.

Delayed cerebral ischemia: A worsening in neurologic function in a subarachnoid hemorrhage patient, occurring several days after the initial bleed, not due to another cause.

Delusion: Fixed, false beliefs that are not based in reality or consistent with the patient’s religion or culture. Delusions can be classified as paranoid, somatic, or grandiose in nature. Delusions are often unshakable in spite of evidence to the contrary.

Dementia: A chronic progressive neurodegenerative syndrome characterized by a decline in memory and at least one other cognitive function.

Demyelination: Destruction of myelin in the spinal cord and brain leading to the formation of plaques that impair communication between neurons. Demyelination is classically found in the central nervous system of patients with multiple sclerosis and may be reversible.

Depersonalization: A change in an individual’s self-awareness, such that one feels detached from his or her own experiences, with the self, body, and mind seeming alien or distant. Persistent or recurrent experiences as if one is an outside observer of one’s mental processes or body (e.g., feeling like one is in a dream).

Derealization: A feeling of estrangement or detachment from one’s environment.

Dermatitis: Inflammation of the skin.

Dermatophyte: Fungal infection of the skin.

Dermis: The inner layer of skin between the epidermis and hypodermis.

Desensitization: Administration of increasing doses of drug to achieve patient tolerance and avoidance of hypersensitivity reactions.

Detoxification programs: A medically supervised treatment program for alcohol or drug addiction designed to purge the body of intoxicating or addictive substances. Such a program is used as a first step in overcoming physiologic or psychologic addiction.

Detumescence: Process by which an erect penis becomes flaccid.

Diagnostic overshadowing: Underestimating the significance of the emotional disturbances because of the presence of significant cognitive deficits.

Dialysate: The cleansing solution used in dialysis to remove excess fluids and waste products from the blood.

Dialysis: The process of removing toxic substances and fluid across a semipermeable membrane to maintain fluid, electrolyte, and acid–base balance.

Diaphragm: (1) A flexible ring covered with rubber or other plastic material, fitted over the cervix of the uterus to prevent pregnancy. (2) Muscular membrane separating the abdominal and thoracic cavities, used for respiration.

Diaphoresis: Perspiration.

Diastolic blood pressure: The arterial BP that occurs after cardiac contraction when the cardiac chambers are filling.

Diastolic heart failure: A condition caused by increased resistance to the filling of one or both ventricles; this leads to symptoms of congestion from the inappropriate upward shift of the diastolic pressure-volume relation.

Diffuse idiopathic skeletal hyperostosis (DISH): A form of degenerative arthritis caused by calcification or a bony hardening of ligaments alongside the vertebrae of the spine. Also known as Forestier disease.

Diffuse idiopathic skeletal hyperostosis (DISH): Abnormal bone formation with calcifications and ossifications along the anterolateral aspect of vertebral bodies. A variant of Forestier disease.

Diffusion-weighted imaging: A type of magnetic resonance imaging (MRI) that can sensitively detect changes in water movement in tissue. It is particularly sensitive to the early changes seen during brain ischemia.

Digital clubbing: Rounded and swollen tip of finger usually associated with long-term pulmonary disease.

Dihydrotestosterone: The active androgen metabolite, which is formed inside various cells. In the case of benign prostatic hyperplasia (BPH), dihydrotestosterone is formed inside prostate cells by the action of 5-α-reductase, which converts testosterone to dihydrotestosterone. Dihydrotestosterone stimulates the glandular portion of the prostate to undergo hyperplasia.

Disinhibition: A physiologic effect that occurs during psychoactive substance use characterized by a loss of normal, executive functioning and normal behavior. An increase in behaviors with the propensity to harm the individual is common.

Dissociative amnesia: Inability to remember some important aspect of an event.

Diverticulitis: Inflammation of a diverticulum, especially of the small pockets in the wall of the colon that fill with stagnant fecal material and become inflamed; rarely, they can cause obstruction, perforation, or bleeding.

Dopamine: A monoamine neurotransmitter formed in the brain by the decarboxylation of dopa and essential to the normal functioning of the central nervous system.

Doppler imaging: With Doppler imaging, a probe generates sound waves typically at 2.5 MHz. When encountering an object, sound waves are scattered or reflected back toward the probe from the object’s interface with adjacent structures; this is repeated in many times per second to build up a moving real-time image of the heart.

Drug abuse: A maladaptive pattern of substance use indicated by repeated adverse consequences related to the repeated use of the substance. Examples include failure to fulfill important obligations at work, school, or home; repeated use in situations in which it is physically dangerous, such as driving under the influence; legal problems; and social or interpersonal problems such as arguments and fights.

Drug addiction: A chronic disorder characterized by the compulsive use of a substance resulting in physical, psychologic, or social harm to the user and continued use despite that harm.

Dual diagnosis: A developmentally disabled person comorbid with a psychiatric disorder.

Dumping syndrome: A condition characterized by weakness, dizziness, flushing/warmth, nausea, and palpitation immediately or shortly after eating and produced by abnormally rapid emptying of the stomach, particularly in individuals who have had part of the stomach removed.

Dysentery: Diarrhea characterized by blood, mucus, and leukocytes in the stool with tenesmus and fever.

Dyskinesia: Choreiform abnormal involuntary movements involving usually the face, neck, trunk, and extremities.

Dysmenorrhea: Crampy pelvic pain occurring with or just prior to menses. Primary dysmenorrhea implies pain in the setting of normal pelvic anatomy, whereas secondary dysmenorrhea is secondary to underlying pelvic pathology.

Dyspareunia: Painful sexual intercourse.

Dyspepsia: Literally means “bad digestion” but refers to persistent or recurrent pain or discomfort centered in the upper abdomen. Symptoms may include epigastric pain, bloating, abdominal distention, postprandial fullness, early satiety, and nausea.

Dysphagia: Difficulty swallowing.

Dysphoria or dysphoric: A feeling of discomfort or an unpleasant mood, such as sadness, anxiety, or irritability.

Dyspnea: Dyspnea is referred to as shortness of breath or difficulty or distress in breathing.

Dystonia: Sustained muscular spasm or abnormal postures.

Early empirical therapy: The administration of systemic antifungal agents at the onset of fever and neutropenia.

Economic outcomes: The direct, indirect, and intangible costs compared with the consequences of a medical intervention.

Edema: Accumulation of fluid in tissues.

Effective renal plasma flow (ERPF): The flow of plasma through the kidneys; often measured by p-aminohippurate (PAH) clearance and expressed in volume per unit of time (mL/min). The ERPF is less than the true renal plasma flow (RPF) because plasma flow through renal connective and adipose tissue is not measured and the extraction of PAH, although high (>0.9), is not complete.

Ejaculatory dysfunction: This is a type of sexual dysfunction that can present as premature ejaculation (before orgasm has occurred), anejaculation (failure of emission), or retrograde ejaculation (when ejaculate moves backward into the bladder as opposed to forward and out of the body during orgasm). In some cases, ejaculatory dysfunction can decrease sexual enjoyment in the patient.

Ejection fraction: The ejection fraction is the percentage of blood ejected from the left ventricle with each heart beat.

Elation: An exaggerated feeling of well-being, euphoria, or elation.

Electroconvulsive therapy: A treatment for severe mental illness in which a precisely calculated electric stimulus is administered in a controlled medical setting to produce a generalized seizure.

Electroencephalograph (EEG): Used to evaluate brain electrical activity.

Electroencephalography: A test that measures electrical brain wave activity through the use of multiple scalp electrodes.

Electromyography: Test of muscle function because of either primary muscle disease or secondary to nerve injury.

Embolism: The sudden blockage of a vessel caused by a blood clot or foreign material that has been brought to the site by the flow of blood.

Embolization: The process by which a blood clot or foreign material dislodges from its site of origin, flows in the blood, and blocks a distant vessel.

Emergency contraception: Any method of contraception that acts after intercourse to prevent pregnancy.

Emesis: See Vomiting.

Empirical therapy: With systemic antifungal agents is administered to granulocytopenic patients with persistent or recurrent fever despite the administration of appropriate antimicrobial therapy.

Enanthem: Eruption on a mucous membrane (as the inside of the mouth) occurring as a symptom of a disease.

Encephalitis: Inflammation of the brain tissue.

Encephalopathy: An altered brain state that may occur with altered brain structure. Many etiologies are associated with encephalopathy (toxins, cancer, metabolic disorders, CNS infections, increased cranial pressure, radiation, alcohol, psychotropic drugs, trauma, inadequate nutrition, decreased brain oxygen, and CNS injury). Consciousness is impaired with patients having a decreased/altered mental state and diffuse slowing of the EEG.

End-stage kidney disease: Glomerular filtration rate (GFR) <15 mL/min/1.73 m2 (<0.14 mL/s/m2) or need for renal replacement therapy.

Endobronchitis: Inflammation of the epithelial lining of the bronchi.

Endocarditis: An infection of the endocardial surface of the heart, which can include one or more heart valves, the mural endocardium, or a septal defect.

Endocrine therapy: A group of drugs used to treat cancer that target the production or action of endogenous hormones.

Endometriosis: Presence of endometrial tissue outside the uterus.

Endoscopy: A diagnostic tool used to examine the inside of the body using a lighted, flexible instrument called an endoscope.

Enkephalins: Pentapeptide endorphins, found in many parts of the brain, that bind to specific receptor sites, some of which can be pain-related opiate receptors.

Enteric fever: Intestinal inflammation and ulceration with high fever and abdominal complaints caused by infection.

Enterocolitis: Inflammation of the small intestine and colon.

Enterotoxin: A cholera-like disease that produces secretory diarrhea.

Enuresis: Urinary incontinence, especially at night.

Enzymuria: Presence of enzymes in the urine.

Epidermis: The outer layer of skin.

Epigenetic: A change in the genome that is heritable and potentially reversible that does not alter the nucleotide sequence of DNA.

Epilepsy: Two or more unprovoked seizures; symptoms of disturbed electrical activity in the brain.

Epilepsy syndrome: The combination of seizure type with other components of the patient history such as age of onset, intellectual development, findings on neurologic examination, and results of neuroimaging.

Episodic: Recurring and remitting in a regular or irregular pattern.

Epistaxis: Nose bleed.

Epithelial cells: Cells that make up epithelium.

Epithelial tissue of the prostate: Also known as glandular tissue. This portion of the prostate is responsible for producing prostatic secretions, and this comprises only approximately 25% of the total volume of the enlarged prostate gland in patients with benign prostatic hyperplasia. Epithelial tissue is androgen dependent.

Epithelium: Layer of avascular cells covering body surfaces.

Erectile dysfunction: Also known as impotence. This is a failure of the penis to become rigid enough to allow for vaginal penetration of the sexual partner.

Erysipelas: Infection of the more superficial layers of the skin and cutaneous lymphatics.

Erythema: Redness.

Erythema multiforme: Symmetrical patches of raised, red skin.

Erythema nodosum: Raised, red, tender nodules on the skin that vary in size from 1 cm.

Erythroderma: Generalized redness of the skin.

Erythropoiesis: The production of erythrocytes (red blood cells) within the bone marrow.

Erythropoietic agents: Agents developed with recombinant DNA technology that have the same biologic activity as endogenous erythropoietin to stimulate red blood cell production. Available agents in the United States include epoetin alfa and darbepoetin alfa.

Erythropoietin: A hormone made by the kidneys that is required for red blood cell formation in the bone marrow. Lack of this hormone leads to anemia.

Eschar: Black, painless skin ulcer characteristic of cutaneous anthrax.

Esophageal: Involving the esophagus.

Esophageal stricture: A narrowing of the esophageal lumen because of acid reflux into the lower esophagus.

Esophagitis: Inflammation of the esophagus.

Essential hypertension: Persistently elevated BP that results from unknown pathophysiological etiology.

Essential or primary hypertension: Persistently elevated blood pressure that results from unknown pathophysiological etiology.

Estrogen therapy: Unopposed estrogen regimens administered to postmenopausal women following hysterectomy.

Euphoria: A mood state characterized by an exaggerated, superficial sense of well-being, characterized extreme happiness, sometimes more than is reasonable in a particular situation.

Euthymia or euthymic: A mood in a normal range without depression or mood elevation.

Evidence-based medicine (EBM): Evidence-based medicine emphasizes the consideration of results from clinical research as the basis for clinical decision making. Under this practice approach, unless individual patient-specific factors dictate otherwise, treatment should generally be guided by those approaches that have the best research evidence for efficacy, tolerability, and patient acceptance.

Evoked potentials: EEG-based technique involving measurement of brain-wave activity in response to stimuli, usually visual or auditory.

Exanthema: An eruption on the skin occurring as a symptom of a disease.

External beam radiotherapy: Treatment by radiation emitted from a source located at a distance from the body; also called beam therapy and external beam therapy.

Extrapyramidal: Regarding involuntary motor movement.

Extrapyramidal system: Neurotransmitter tracts in the midbrain with dopamine as the primary ascending neurotransmitter, with cell bodies in the substantial nigra and axons terminating in the basal ganglia (e.g., caudate nucleus, putamen). The extrapyramidal system is largely involved in the control of fine motor movements, and with some degree of emotional expression as well.

Fasciculations: The localized contractions of muscle groups, often visible through the skin, because of excessive neuronal discharge.

Fear: A direct, focused response to a specific event or object of which an individual is consciously aware.

Felty syndrome: Rheumatoid arthritis associated with splenomegaly and neutropenia.

Fibrin: An insoluble protein that is one of the principle ingredients of a blood clot. Fibrin strands bind to one another to form a fibrin mesh. The fibrin mesh often traps platelets and other blood cells.

Fibromyalgia: A syndrome characterized by chronic widespread pain, multiple tender points, abnormal pain, sleep disturbances, fatigue, and psychological distress.

Fibrosis: Formation of fibrous tissue as a reparative or reactive process.

First-degree relative (FDR): A close blood relative, including the individual’s parents, full siblings, and children.

First-generation (typical or traditional) antipsychotic: An antipsychotic medication with a mechanism of action thought to be primarily caused by the blockade of dopamine-2 (D2) receptors. D2-blockade is associated with hyperprolactinemia and extrapyramidal side effects.

Fistula: A communicating tube-like passage from one organ to another or from an organ to an external surface; often seen in severe cases of Crohn’s disease.

Flight of ideas: An accelerated flow of speech with thoughts that change rapidly from one topic to another.

Focal seizures: Partial seizures.

Follicle-stimulating hormone (FSH): A polypeptide hormone secreted by the anterior pituitary gland that promotes ovarian follicle development and stimulates estradiol and progesterone.

Fragile X syndrome: A genetic disorder commonly associated with mental retardation in which the tip of the long arms of the X chromosome separates from the rest of the genetic material; most males and 30% of females with fragile X syndrome have mental retardation; males develop enlarged testicles, enlarged ears, and a prominent jaw.

Freezing: Intermittent immobility lasting a few seconds, particularly in walking, seen in Parkinsonism.

Fulminant hepatitis: Acute hepatic failure; rare complication of viral hepatitis, it can also result from hepatotoxins, or drug sensitivity and causes massive necrosis of the liver; marked by a high fatality rate.

Functional analysis: Evaluation performed by a psychologist qualified in applied behavioral analysis to determine if a behavior is caused by some environmental factor.

Functional pain: Pain due to abnormal operation of the nervous system.

Functional psychiatric disorder: A mental disorder that is primarily defined by a constellation of symptoms and behaviors and for which the pathophysiologic etiology is still largely unknown.

Fungemia: The presence of fungi in the blood.

Gastroesophageal reflux disease (GERD): Symptomatic clinical condition or histologic alteration that results from episodes of gastroesophageal reflux.

Gene: Series of codons that specify a particular protein.

Generalized anxiety disorder (GAD): Excessive anxiety and worry about a number of events or activities occurring more days than not for a period of at least 6 months.

Generalized convulsive status epilepticus (GCSE): Most common and dangerous type of status epilepticus. It consists of bilateral (both brain hemispheres) electrical seizure activity that manifests as tonic and/or clonic motor activity. The convulsions and/or brain discharges can be symmetrical or asymmetrical (i.e., parts of body and brain mirroring or not mirroring each other in activity). Consciousness is not maintained during the seizures episodes. The duration is sufficient enough in length to meet the definition of status epilepticus.

Generalized seizures: Seizures occurring in both hemispheres of the brain. They can be primary or secondarily generalized.

Generic/general measures: Instruments designed to be applicable across a wide variety of conditions/diseases, medical interventions, and populations.

Germ-line mutations: Inherited variations in germ cells that are transmitted to offspring compared with variations in somatic cells, which are not passed on to offspring.

Genotype: The genetic constitution of an individual.

Genu valgum: A deformity marked by lateral angulation of the leg in relation to the thigh.

Genu varum: A deformity marked by medial angulation of the leg in relation to the thigh; an outward bowing of the legs.

Gestation: Time from fertilization of egg until birth.

Gigantism: Excess secretion of growth hormone prior to epiphyseal closure in children.

Glasgow coma scale: The most widely used system to grade the arousal and functional capacity of the cerebral cortex consisting of eye opening, motor responses, and verbal responses.

Glaucoma: Any of a group of ocular disorders that lead to an optic neuropathy characterized by changes in the optic nerve head (optic disk) that is associated with loss of visual sensitivity and field. Open angle and closed angle are the two major types of glaucoma.

Glomerular filtration rate (GFR): The primary index of overall kidney function; the volume of plasma that is filtered by the glomerulus per unit of time; often reported in mL/min or mL/min/1.73 m2.

Glomerulonephritis: Glomerular lesions characterized by inflammation of the capillary loops in the glomerulus caused by immunologic, vascular, and other idiopathic diseases (may be diffuse or membranoproliferative).

Glomerulosclerosis: Fibrosis of the glomeruli.

Glomerulus: A coiled capillary bed in the kidney that is responsible for filtering water and small molecular weight substances from the blood.

Gonadotropin: A sex hormone that promotes gonadal growth and functioning in both males and females.

Gonadotropin-releasing hormone (GnRH): A trophic hormone released by the hypothalamus that stimulates release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

Gout: A disease spectrum that includes hyperuricemia, recurrent attacks of acute arthritis associated with monosodium urate crystals in leukocytes found in synovial fluid, deposits of monosodium urate crystals in tissues (tophi), interstitial renal disease, and uric acid nephrolithiasis.

gp120: The glycoprotein structure on the surface of human immunodeficiency virus (HIV) that binds to CD4 on human cells.

Grandiosity: An inflated self-appraisal of one’s status, power, or identity.

Granuloma inguinale: Granuloma lesions affecting the genital area.

Growth hormone (GH): A polypeptide hormone secreted by the anterior pituitary gland that stimulates insulinlike growth factor-1 (IGF-1) production and promotes growth of all body cells.

Growth hormone-releasing hormone (GHRH): A trophic hormone released by the hypothalamus that stimulates release of growth hormone.

Guillain-Barré’s syndrome: A disorder characterized by progressive symmetrical paralysis and loss of reflexes, usually beginning in the legs. The paralysis typically involves more than one limb, is progressive, and usually proceeds from the end of an extremity toward the torso. Areflexia or hyporeflexia can occur in the limbs. It typically occurs after recovery from a viral infection.

Gumma: A granulomatous lesion found in organs or tissues as a result of syphilis.

Gynecomastia: Gynecomastia is the abnormal development of large breasts in men.

Half-life: The time required for serum concentrations to decrease by one-half after absorption and distribution are complete.

Hallucination: A sensory perception (e.g., auditory, gustatory, olfactory, somatic, tactile, visual) that occurs without external stimulation of the relevant sensory organ.

Haplotype: Set of polymorphisms that are inherited together.

Haptocorrin: A group of carrier proteins that bind with vitamin B12 in the blood and aid in its transport.

Haptoglobin: A group of α2-globulins in human serum, so called because of their ability to combine with hemoglobin, preventing loss in the urine; levels are decreased in hemolytic disorders and increased in inflammatory conditions or with tissue damage.

Hay fever: See Rhinitis.

Health literacy: The degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions (as defined by the Institute of Medicine).

Health outcomes: The consequences or ends results of a disease and/or its treatment.

Health profiles: Generic instruments that provide an array of scores representing individual dimensions or domains of health-related quality of life (HRQOL) or health status.

Health-related quality of life (HRQOL): A person’s perception of how health impacts his or her physical, social, and psychologic functioning and well-being.

Health state preference: The perceived relative desirability of a health state measured on a scale where 1.0 equals full health, and 0.0 equals dead.

Heart failure: A clinical syndrome that can result from any disorder that impairs the ability of the heart to fill with or eject blood. Although heart failure may be caused by numerous cardiac disorders, the primary clinical signs and symptoms of dyspnea, fatigue, and volume overload are similar regardless of the initial cause.

Heinz bodies: Intracellular inclusions usually attached to the red cell membrane composed of denatured hemoglobin.

Hemagglutinin: The major antigenic determinant of the influenza virus; a surface antigen that allows the influenza virus to enter host cells by attaching to sialic acid receptors.

Hematemesis: Vomiting up blood that can be bright red or similar to coffee grounds in appearance.

Hematochezia: The presence of visible bright red blood in the stool.

Hematopoiesis: The formation and maturation of blood cells and their derivatives.

Hematopoietic growth factors: See Colony-stimulating factors.

Hematopoietic stem cell: An immature cell capable of self-renewal and subsequent differentiation into mature blood cells.

Hematuria: Presence of red blood cells in the urine.

Hemetemesis: Vomiting up blood that may be bright red or appear like coffee grounds. The digestive action of acid and enzymes may cause blood in the stomach to darken and appear like coffee grounds in the vomitus.

Hemochromatosis: Hemochromatosis is a disorder that interferes with iron metabolism, which results in excess iron deposition throughout the body.

Hemodialysis: A dialysis procedure during which blood is pumped outside the body through a dialyzer that acts like an artificial kidney; the dialyzer removes extra fluids and wastes from the blood and returns the clean blood to the body.

Hemolytic uremic syndrome: A condition characterized by the breakup of red blood cells (hemolysis) and kidney failure. Platelets clump together within the kidney’s small blood vessels resulting in ischemia leading to kidney failure.

Hemosiderin: A golden yellow or yellow-brown insoluble protein produced by phagocytic digestion of hematin; found in most tissues, especially in the liver, spleen, and bone marrow, in the form of granules much larger than ferritin molecules (of which they are believed to be aggregates) but with a higher content, as much as 37%, of iron.

Heparin-induced thrombocytopenia: A clinical syndrome of IgG antibody production against the heparin–platelet factor 4 complex occurring in approximately 1% to 5% of patients exposed to either heparin or low-molecular-weight heparin. Heparin-induced thrombocytopenia results in excess production of thrombin, platelet aggregation, and thrombocytopenia (due to platelet clumping), often leading to venous and arterial thrombosis, amputation of extremities, and death.

Hepatosplenic candidiasis: Clinical presentation often manifested only as fever while a patient remains neutropenic (<1,000 white blood cells/mm3). When the white blood cell (WBC) count increases to >1000 cells/mm3, imaging studies can detect the presence of abscess or microabscesses in the liver and spleen, often found with acute suppurative and granulomatous reactions. Infection can persist for months and ultimately cause the patient’s death despite aggressive systemic therapy with antifungal agents.

Heterozygous: Presence of different (alleles) genes at one location.

Hippocampal sclerosis: A condition in which there is histopathological changes in the hippocampus that have been associated with patients with a history of prolonged status epilepticus. There is an association with hippocampal sclerosis and temporal lobe epilepsy.

Hippocampus: A sea horse–shaped structure located within the brain that is an important part of the limbic system. The hippocampus is involved in some aspects of memory, in the control of the autonomic functions, and in emotional expression.

Hirsutism: Heavy, abnormal growth of hair on the face or body; excess body hair appearing on the lower abdomen, around the nipples, around the chin and upper lip, between the breasts, and on the lower back.

HLA (human leukocyte antigen): See Human leukocyte antigen.

Hollenhorst plaque: Cholesterol emboli that usually dislodges from the carotid arteries, or calcific fragments from a stenosed aortic valve that can be visualized on a retinal exam.

Homocysteine: A homolog of cysteine, produced by the demethylation of methionine, and an intermediate in the biosynthesis of 1-cysteine from 1-methionine through 1-cystathionine. Elevated levels of homocysteine have been associated with certain forms of heart disease.

Homozygous: Presence of identical genes (alleles) at one location.

Hormone therapy: Either estrogen-only therapy or combined estrogen and progestogen therapy.

Hot flashes/flushes: A sensation of warmth, frequently accompanied by skin flushing and perspiration.

Human leukocyte antigen (HLA): The self antigens are the histocompatibility antigens found on human leukocytes and tissues that enable the body to differentiate self from foreign cells. The HLA antigens are used in histocompatibility testing to determine the suitability of an organ for transplant.

Humanistic outcomes: Patient-reported outcomes such as patient satisfaction and health-related quality of life.

Hydrocephalus: An uncharacteristic increase in the amount of cerebrospinal fluid within the skull, causing dangerous expansion of the cerebral ventricles.

Hyperalgesia: Exaggerated painful response to normally noxious stimuli.

Hyperarousal: A state of elevated or increased alertness, awareness, or wakefulness.

Hypercapnia: Elevation of carbon dioxide gas in the blood.

Hypercoagulable state: A disorder or state of excessive or frequent thrombus formation; also known as thrombophilia.

Hypereosinophilic syndrome: Hypereosinophilic syndrome is a group of leukoproliferative disorders characterized by an overproduction of eosinophils resulting in organ damage.

Hyperkalemia: Serum potassium concentration above 5.5 mEq/L.

Hyperlinear palms: Increased number of skin creases on the palms.

Hypermagnesemia: Serum magnesium concentration above 1.8 mEq/L or 2.3 mg/dL.

Hyperpigmentation: Excess pigment in skin causing an area of darker color than surrounding skin.

Hyperprolactinemia: A state of persistent serum prolactin elevation characterized by prolactin concentrations greater than 20 mcg/L observed on multiple occasions.

Hyperresponsiveness: In the airways, the characteristic of an exaggerated response to stimuli.

Hypertensive crises: Clinical situations where BP values are very elevated, typically greater than 180/120 mm Hg. They are categorized as either a hypertensive emergency or hypertensive urgency depending on the clinical presentation.

Hypertensive emergency: A clinical situation in which a patient has extremely high BP values, typically greater than 180/120 mm Hg that is also accompanied by the presence of acute and/or progressing target-organ damage. Immediate but gradual reduction in BP using intravenous antihypertensive agents is needed to prevent acute morbidity and/or mortality.

Hypertensive urgency: A clinical situation in which a patient has extremely high BP values, typically >180/120 mm Hg, that is not accompanied by acuter or progressing target-organ injury. These situations require oral antihypertensive therapy to reduce BP to Stage 1 values over a period of several hours to several days.

Hypertrichosis: Abnormal hair growth on the body in areas where hair does not usually grow.

Hypertrophic cardiomyopathy: Hypertrophic cardiomyopathy is a genetic disorder characterized by disproportionate hypertrophy of the left ventricle, and occasionally of the right ventricle.

Hypervigilance: An enhanced state of sensory sensitivity accompanied by an exaggerated intensity of behaviors whose purpose is to detect threats.

Hypnagogic hallucinations: Dreamlike experiences on the threshold of sleep that intrude into wakefulness.

Hypnopompic hallucinations: Dreamlike experiences on the threshold of awakening that intrude into wakefulness.

Hypochlorhydria: Presence of an abnormally small amount of hydrochloric acid in the stomach.

Hypogonadism: Little or no hormone production by the testes (in men) or ovaries (in women).

Hypokalemia: Serum potassium concentration below 3.5 mEq/L.

Hypomagnesemia: Serum magnesium concentration below 1.4 mEq/L or 1.7 mg/dL.

Hypomania: An abnormally and persistently elevated, expansive, or irritable mood resembling mania, but of lesser intensity and which does not cause marked impairment in functioning.

Hypomimia: Decreased facial expression often associated with decreased blink rate.

Hypophonia: Decreased volume of speech.

Hypothalamus: A small region at the base of the brain that controls the release of hormones from the anterior and posterior regions of the pituitary gland and regulates limbic functions, fluid balance, body temperature, cardiovascular function, respiratory function, and diurnal rhythms.

Hysterectomy: Excision of the uterus.

Hysteresis: A situation in which concentration-effect curves do not always follow the same pattern when serum concentrations increase as they do when serum concentrations decrease. Can result from tolerance to a drug (clockwise hysteresis) or accumulation of active metabolites (counterclockwise hysteresis).

Iatrogenesis or iatrogenic disease: A disease produced as a consequence of medical or surgical treatment.

Ichthyosis: Dry, rectangular scales on the skin.

Ictal: The period during a seizure.

Icteric: Relating to or marked by jaundice.

Idiopathic: Unknown etiology of status epilepticus, often considered a genetic etiology for the prolonged seizure; definition specific to seizures, but really applies to any disease.

Ileitis: Inflammation of the ileus.

Illusions: Visual perceptions that are misinterpreted but have a real sensory stimulus.

Immunocompromised host: A patient with defects in host defenses that predispose him or her to infection (risk factors can include neutropenia, immune system defects from disease or immunosuppressive drug therapy, compromise of natural host defenses, environmental contamination, and changes in normal flora of the host).

Immunoglobulin: Structurally related glycoproteins that function as antibodies and are divided into classes on the basis of structure/biologic activity.

Impaction: An immovable packing; a lodgment of something in a strait or passage of the body; as, impaction of the fetal head in the strait of the pelvis; impaction of food or feces in the intestines of man or beast.

Impedance-pH monitoring: New technique used to detect reflux by measuring changes in intraluminal resistance determined by the presence of liquid or gas inside the esophagus. When combined with pH monitoring, it can differentiate between acid and nonacid reflux.

Impending status epilepticus: Any seizure that does not stop automatically within 5 minutes has been termed impending status epilepticus. This is a fairly new term that was created to recognize the importance of early treatment of status epilepticus. Pharmacologic and nonpharmacologic treatment of status epilepticus should be initiated for those seizures that do not spontaneously terminate within 5 minutes.

Impetigo: A superficial skin infection that is seen most commonly in children.

Implantable cardioverter-defibrillator (ICD): The ICD is a surgically implanted electronic device that monitors, detects, and treats potentially life-threatening ventricular tachycardia with rate-responsive ventricular pacing.

Inanition: Severe weakness and wasting as occurs from lack of food, defect in assimilation, or neoplastic disease.

Incubation period: The time between exposure of a biologic (i.e., pathogen), chemical, or radiologic substance and when symptoms first start to appear (also known as latency).

Induction: Administration of a highly intense level of immunosuppression in the perioperative period or use of antibody therapy to provide enough immunosuppression to delay administration of nephrotoxic calcineurin inhibitors.

Infant mortality: Deaths occurring in those younger than the age of 1 year per 1,000 live births.

Infants: Pediatric patients who are 1 month to 1 year of age.

Infarction: The formation of an infarct, an area of tissue death due to a local lack of oxygen.

Infection: Inflammatory response to invasion of host tissue by microorganisms.

Information bias: A flaw in measuring exposure or outcome data that results in systematic differences in the quality of information gathered for study and comparison groups. See also Selection bias.

Instrumental activities of daily living: Housekeeping chores, shopping, going outside, medication management. See also Activities of daily living.

Insulin-like growth factor-1: An anabolic peptide that acts as a direct stimulator of cell proliferation and growth in all body cells.

Integumentary system: Skin, subcutaneous tissue, and skin appendages.

Intravenous fat emulsion: An intravenous oil-in-water emulsion of oil(s), egg phosphatides, and glycerin.

Interleukin: A type of cytokine, usually influencing a white blood cell.

Intermittent-combined estrogen-progestogen therapy: A regimen that combines a daily estrogen with a progestogen administered intermittently in cycles of 3 days on and 3 days off (which is then repeated without interruption).

International normalized ratio (INR): A measure of coagulation calculated from the patient’s prothrombin time (PT) measurement compared to the laboratory’s mean normal control measurement and takes into account the sensitivity of the thromboplastin used to perform the test.

Interpersonal psychotherapy: A psychologic intervention that focuses on interpersonal relationships and psychosocial functioning.

Interpretability: The degree to which one can assign qualitative meaning to an instrument’s quantitative scores.

Intertriginous areas: Body fold areas (e.g., between buttocks, beneath breasts, between toes, under arms).

Intertrigo: An inflammatory condition of skinfolds induced or aggravated by heat, moisture, maceration, friction, and lack of air circulation.

Intoxication: The development of a substance-specific syndrome after recent ingestion and presence in the body of a substance; associated with maladaptive behavior during the waking state caused by the effect of the substance on the central nervous system.

Intracavernosal injection: Injection into the corpus spongiosum.

Intracranial hypertension: Excessive pressure (>20 mm Hg) within the nondistensible intracranial cavity (i.e., skull) that can develop following traumatic brain injury.

Intracranial pressure: The pressure of the cerebral spinal fluid that is essentially the same as the pressure within the brain tissue (i.e., intraparenchymal pressure).

Intraperitoneal: Within the peritoneal cavity.

Intrauterine device: A device inserted in the uterus to prevent pregnancy, either through spermicidal action (copper device) or thickening cervical mucus to inhibit sperm penetration and migration (progesterone device).

Intrinsic resistance: See Primary resistance.

Intussusception: Invagination of one portion of the intestine into an adjacent part of the intestines.

Inulin: A fructose polysaccharide that is filtered by the glomerulus; its clearance is often used as an index of GFR.

Iothalamate: A nonradiolabeled or radiolabeled iodinated contrast agent that is filtered by the glomerulus; its clearance is often used as an index of GFR.

Ipsilateral: Of or pertaining to the same side of the body.

Irritable: Easily annoyed and provoked to anger.

Irritative voiding symptoms: Urinary urgency and frequency. This results from detrusor muscle decompensation that results from long-standing bladder outlet obstruction.

Isolated systolic hypertension: Patients with DBP values that are less than or equal to 90 mm Hg and SBP values that are greater than or equal to 140 mm Hg.

Janeway lesion: These lesions appear as flat, painless, red to bluish-red spots on the palms and soles of patients with acute bacterial endocarditis.

Jarisch-Herxheimer reaction: An increase in symptoms of spirochetal disease caused by the initiation of treatment.

J-curve phenomenon (in hypertension): A theoretical situation where lowering BP provides a reduced risk of cardiovascular events, but when BP is lowered too much, can paradoxically increase the risk of cardiovascular events.

Jugular venous oxygen saturation (Sjvo2): Oxygen hemoglobin saturation of blood in the jugular bulb, which is a key element in estimating CMRo2.

Just culture of patient safety: An approach to analysis and prevention of medication errors that relies on encouragement of internal risk transparency, coaching and consoling of employees, avoiding negative retribution for errors, and gathering then using information to prevent error recurrence.

K complexes: Electronegative waves followed by electropositive waves seen on the EEG during sleep.

Karyotyping: Chromosomal analysis.

Keratinization: Keratin formation.

Keratinized: Skin that has developed thicker areas of keratin in the stratum corneum.

Keratinocyte: Cell of the epidermis that produces keratin.

Keratoconjunctivitis sicca: Dry, itchy eyes that result from atrophy of the lacrimal ducts, which can be seen in inflammatory arthritis.

Keratolytic: Agent that solubilizes intracellular cement of keratin cells in the stratum corneum.

Keratosis pilaris: Small, rough bumps, generally on the face, upper arms, and thighs.

Ketogenic diet: A special antiseizure diet that is high in fat and low in carbohydrates and protein.

Kleptomania: An impulse control disorder characterized by frequent and repeated theft.

Köbner phenomenon: De novo lesion psoriasis appearing at the site of cutaneous trauma.

Kt/V: A measurement of how much urea is being removed from the blood during dialysis. The measurement takes into account the efficiency of the dialyzer (clearance, K), the treatment time (t), and the volume of distribution of urea (V).

Kussmaul sign: Kussmaul sign is a rise in jugular venous pressure on inspiration. Kussmaul sign is seen in conditions in which there is right ventricular filling.

Kwashiorkor: Starvation-associated malnutrition associated with inadequate protein intake.

Lactation: Production and secretion of breast milk.

Lanugo: Fine body hair normally found on a fetus. The hair develops in patients with anorexia nervosa when they are very underweight and malnourished.

Laparoscopic: Abdominal exploration or surgery employing a type of endoscope called laparoscope.

Laparotomy: Surgical opening of the abdominal cavity.

Laryngospasm: The spasmodic closure of the larynx because of a variety of causes such as allergic reactions, response to irritants, and pharmacologic actions.

Lavage: Washing out.

Laxative: A medication or agent used to produce a bowel movement.

Left ventricular ejection fraction: Also known simply as the ejection fraction, it is the fraction or percentage of the end-diastolic blood volume ejected by the left ventricle during systole. It is a measurement of cardiac systolic function with a normal ejection being >60% (>0.60). It can be determined noninvasively by an echocardiogram; it is really institution dependent and highly variable. It now states that >60% is normal, but in our institution, >50% is considered normal.

Left ventricular end diastolic volume: Left ventricular end diastolic volume refers to the volume of blood found in the left ventricular at the end of heart relaxation or diastole.

Left ventricular hypertrophy: Enlargement of the left ventricle, which is seen in heart failure and can give rise to arrhythmias.

Lentigines, PUVA: Brown to black macules resulting from long-term use of psoralens plus ultraviolet A light.

Leptospirosis: A bacterial disease that affects humans and animals caused by the genus Leptospira.

Lewy bodies: Pink-staining spheres found inside neuronal cells of the substantia nigra and other brain regions, considered to be a histopathologic marker for Parkinson’s disease.

Lichenification: Thick, leathery skin, usually the result of constant scratching and rubbing.

Linear pharmacokinetics: The situation when changes in long-term daily doses of drugs result in proportional changes in steady state serum drug concentrations. Most drugs follow this pattern.

Linguistic competency: The ability of individuals and organizations to communicate effectively with people from diverse language backgrounds.

Linkage disequilibrium: Two or more polymorphisms that are inherited together more frequently than would be expected based on chance.

Lipid peroxidation: A pathophysiologic process involving the iron-catalyzed attack of lipid membranes by reactive oxygen species.

Liposomes: Spherical amphiphilic vesicles capable of sustained release of water-soluble substances.

Locus ceruleus: A small area in the brainstem containing norepinephrine neurons that is considered to be a key brain center for anxiety and fear.

Low-glycemic-load diet: A low-glycemic-load diet emphasizes consuming carbohydrates with a low glycemic index. To eat a low-glycemic-load diet, avoid foods such as white bread, refined cereal, cookies, and sugary drinks. Emphasize fruits, vegetables, legumes, and minimally processed grains.

Low glycemic index: The term low glycemic index refers to the quality of carbohydrates and how fast they are absorbed. Foods with a low glycemic index are absorbed more slowly, thus keeping insulin levels more stable.

Lumbar puncture: The procedure used to withdraw cerebrospinal fluid through a needle inserted in the lumbar region of the spinal column.

Luteinizing hormone (LH): A polypeptide hormone secreted by the anterior pituitary gland that stimulates ovulation and maintains the corpus luteum.

Luteolysis: Death of the corpus luteum.

Lymphangitis: An inflammation involving the subcutaneous lymphatic channels.

Lymphocytosis: Increased blood concentration of lymphocytes (>4 × 109 cells/mm3) commonly observed in mononucleosis, pertussis, measles, chickenpox, or lymphoid malignancies.

Lymphedema: A lymphatic obstruction of localized fluid retention and tissue swelling caused by compromised lymphatic system.

Lymphogranuloma venereum: Inflammation of the lymph nodes caused by Chlamydia trachomatis resulting in destruction and scarring of tissue.

Macule: Flat, nonpalpable, variable-colored lesion.

Maculopapular: Skin eruption containing both macules and papules.

Magnetic resonance angiography (MRA): A noninvasive method to evaluate the patency of blood vessels using magnetic resonance imaging.

Magnetic resonance imaging (MRI): An imaging technique based on the magnetic properties of the hydrogen atom. It provides an accurate, computer-processed image that can be more sensitive than computed tomography.

Major depression: A psychiatric disorder in which the patient can present with symptoms of depressed mood, a lack of interest in usual activities or inability to experience pleasure, changes in sleep and eating habits, guilt, reduced energy, thoughts of self-harm, and a sense of helplessness or hopelessness.

Major histocompatibility complex (MHC): A set of genes responsible for most of the proteins on the surface of cells in the body that are responsible for recognition of self.

Mania: An abnormally and persistently elevated, expansive, or irritable mood with increased activity or energy which causes marked impairment in functioning.

Marasmus: Starvation-associated malnutrition.

Masked hypertension: Patients that have elevated BP measurements based on home measurements but have normal BP measurements when measured in a clinical setting. These patients have chronic hypertension but either may not be diagnosed or may have a diagnosis of hypertension that is undertreated.

Mass effect: Distortion or displacement of the brain anatomy because of an implied or apparent mass (such as stroke or tumor).

Mastalgia or mastodynia: Pain in the breast.

Mean arterial pressure: The mean arterial pressure is the product of the cardiac output and systemic vascular resistance. Since the cardiac output is pulsatile, rather than continuous, and since 2/3 of the normal cardiac cycle is spent in diastole, the mean arterial pressure is not the arithmetic mean of the systolic and diastolic blood pressures. Mean arterial pressure = diastolic blood pressure + 1/3 (systolic blood pressure – diastolic blood pressure).

Measurement model: An instrument’s scale and subscale structure and the procedures followed to create scale and subscale scores.

Meconium ileus: Intestinal obstruction caused by meconium.

Medication error: Any preventable event that may cause or lead to inappropriate medication use or patient harm while the medication is in the control of the healthcare professional, patient, or consumer (per the National Coordinating Council for Medication Error Reporting and Prevention).

Megakaryocytes: Precursors of platelets.

Melanin: Dark pigment that is part of determining skin color.

Melena: Dark-colored stools resulting from upper gastrointestinal bleed.

Membrane stripping: When the cervix is dilated, a practitioner can use a hand to separate the amniotic membranes from the uterus. This technique has been shown to reduce the need for labor induction.

Menarche: The time of the first menstrual period or flow.

Meningitis: Inflammation, usually infectious, of the meninges, a covering of the brain.

Menopause: The permanent cessation of menses following the loss of ovarian follicular activity.

Menorrhagia: Menstrual blood loss of greater than 80 mL per cycle; a more practical definition is heavy menstrual flow associated with problems of containment of flow, unpredictably heavy flow days, or other associated symptoms.

Menses: Periodic bloody discharge from the uterus.

Mental status examination: An objective patient evaluation conducted through a direct patient interview and used to make a diagnosis, assess the course of illness, or determine treatment response.

Meralgia parethetica: A disorder characterized by tingling, numbness, and burning pain in the outer side of the thigh. The disorder is caused by compression of the lateral femoral cutaneous nerve, a sensory nerve to the skin, as it exits the pelvis.

Mesolimbic pathway: A dopaminergic pathway in the brain that connects the ventral tegmental area in the midbrain to the nucleus accumbens in the striatum and is involved in motivation and reward.

Metabolic syndrome: A constellation of metabolic and cardiovascular changes consisting of at least three of the following: obesity, low high-density lipoprotein (HDL), elevated triglycerides, hypertension, and elevated fasting blood glucose.

Metastasis: Movement or spread of disease from one organ or part to new location not directly connected.

Methemoglobin: A form of hemoglobin that occurs when its iron is oxidized to the +3 state, which decreases oxygen binding.

Methionine: The 1-isomer is a nutritionally essential amino acid and the most important natural source of active methyl groups in the body, hence usually involved in methylations in vivo.

Michaelis–Menten kinetics: the situation where changes in steady state serum drug concentrations of drugs are disproportional to changes in long-term daily doses due to alterations in drug metabolism.

Microalbuminuria: A condition in which a small amount of albumin (30–300 mg/day) is present in the urine; often indicates an early stage of chronic kidney disease (CKD).

Microcephalic: Abnormally small head.

Microcomedo: Microscopic lesion formed from the combination of sloughed, clumping keratinocytes reacting with sebum and fatty acids from the sebaceous gland.

Micrographia: Handwriting that is small, trails off in size, or very slow.

Micrometastases: Spread of microscopic cancer cells to secondary sites distant from the primary site.

Midsystolic: Middle of systole.

Migraine aura: Early symptom of an attack of migraine with aura, which is the manifestation of focal cerebral dysfunction. The aura typically precedes the headache.

Mild cognitive impairment: A syndrome characterized by cognitive impairment that is not of sufficient severity to warrant a diagnosis of dementia.

Milia: Small, white cysts containing keratin.

Mixed states: Rapidly alternating mood states (mania and major depressive episodes) that last at least 1 week, and cause marked impairment in functioning.

Molds: Fungal organisms that grow as multicellular branching, thread-like filaments (hyphae) that are either septate (divided by transverse walls) or coenocytic (multinucleate without cross walls). On agar media, molds grow outward from the point of inoculation by extension of the tips of filaments, and then branch repeatedly, interweaving to form fuzzy, matted growths called mycelium. Germ tubes are the beginning of hyphae, which arise as perpendicular extensions from the yeast cell, with no constriction at their point of origin.

Molybdenum (Mo): A bioelement found in a number of proteins.

Monoamine neurotransmitters: Neurotransmitters that contain one amino group and are derived from amino acids such as tyrosine and tryptophan. Include, among others, the catecholamines (dopamine and norepinephrine) and an indoleamine (serotonin).

Mood: A more pervasive and sustained emotional state that colors a person’s perception of the world.

Morbilliform: Maculopapular lesions that become confluent on the face and body.

Mucolytic: The ability to break down mucus.

Mucositis: Inflammation of the mucosa.

Multiattribute health status classification systems: Preference-based HRQOL instruments for which health-state preferences have been derived from population studies. The instruments assess respondents’ health status, and then population preferences are applied to produce the index score.

Multiparity: Condition of having given birth to multiple children.

Multiple-organ dysfunction syndrome (MODS): Presence of altered organ function requiring intervention to maintain homeostasis.

Multiple sclerosis (MS): A demyelinating disease, caused by inflammation, leading to neurologic deficits and often, disability.

Mutism: A state in which a person either has the inability or refuses to speak or vocalize sounds.

Mycotic: A fungal infection.

Myectomy: A surgical removal of the overgrown septal muscle to decrease the outflow tract obstruction.

Myocarditis: Inflammation of the cardiac muscle.

Myoclonic seizures: Brief shock-like muscular contractions of the face, trunk, and extremities. They usually begin in adolescence and are referred to as juvenile myoclonic epilepsy (JME).

Myoclonus: A sudden twitching of muscles or parts of muscles, without any rhythm or pattern.

Myositis: Inflammation of the muscle, characterized by pain, tenderness, and sometimes spasm in the affected area.

Narrowband UVB (NB-UVB): 311 nm ultraviolet B light.

National Kidney Foundation (NKF): A major voluntary health organization that seeks to prevent kidney and urinary tract diseases, improve the health and well-being of individuals and families affected by these diseases, and increase the availability of all organs for transplantation.

Nausea: An unpleasant sensation associated with an awareness of the urge to vomit.

Necrosis: Local death of cells or tissue.

Necrotizing fasciitis: A rare, but very severe infection of the subcutaneous tissue that can be caused by aerobic and/or anaerobic bacteria and results in progressive destruction of the superficial fascia and subcutaneous fat.

Negative symptoms: Those symptoms of schizophrenia that are largely associated with a deficit in psychosocial functioning, emotional expression, and interpersonal interactions. Examples include blunted affect, alogia, decreased interest and involvement in social and occupational activities, and decreased grooming and hygiene.

Neoadjuvant therapy: Any therapy administered before surgical resection of the tumor or cancer, providing benefits related to tumor shrinkage and eradication of micrometastases.

Neonatal: Within the first 4 weeks (28 days) of life.

Neonates: Newborns who are 1 day to 1 month of age.

Nephritis: Inflammation of the kidney.

Nephrolithiasis: Presence of one or more stones in the renal pelvis, collecting system, or ureters.

Nephron: The working unit of the kidney that is comprised of a glomerulus and tubule. Each kidney is made up of approximately 1 million nephrons, which collectively remove drugs, toxins, and fluid from the blood.

Nephropathy: Refers to a pathologic alteration of the kidney.

Nephrotic range proteinuria: Proteinuria >3 g/day associated with glomerular disease and nephrotic syndrome.

Nephrotoxicity: Toxic insult to the kidney.

Nerve conduction studies: Measurement of the speed of electrical conduction through a nerve.

Neuraminidase: The second major antigenic determinant of the influenza virus; a surface antigen that allows the release of new viral particles from host cells by catalyzing the cleavage of linkages to sialic acid.

Neuritic plaques: Hallmark pathologic marker of Alzheimer’s disease comprised of β-amyloid protein and masses of broken neurites.

Neurofibrillary tangles: Hallmark pathologic marker of Alzheimer’s disease derived from abnormal phosphorylation of τ- protein filaments.

Neuropathic pain: Pain due to nervous system damage.

Neuropsychological: Pertaining to a specialty of psychology concerned with the study of the relationships between the brain and behavior, including the use of psychological tests and assessment techniques to diagnose specific cognitive and behavioral deficits and to prescribe rehabilitation strategies for their remediation.

Neutropenia: An abnormally reduced number of neutrophils circulating in peripheral blood; although exact definitions of neutropenia often vary, an absolute neutrophil count of <1000 cells/mm3 indicates a reduction sufficient to predispose patients to infection.

New York Heart Association classification: The New York Heart Association classification provides a simple way of classifying the extent of heart failure. It places patients in one of four categories based on how much they are limited during physical activity.

N-methyl-D-aspartate antagonists: Class of medications that decreases the activity of synaptic glutamate, thus decreasing the likelihood of cell death.

N-methyl-D-aspartate (NMDA) receptors: One of three types of ionotropic postsynaptic glutamate receptors. Upon binding glutamate, these receptors permit the influx of Ca+2 ions and results in brain excitation. These are one of the two primary receptors for excitatory neurotransmission in the brain.

Nociceptive pain: Pain due to physiologic processes that involve transduction, transmission, perception, and modulation.

Nocturia: Frequent nighttime urination (>2 micturitions per night).

Nodule: Elevated, palpable, solid, round or oval lesion more than 0.5 cm in diameter.

Non–ST-segment elevation: A type of myocardial infarction that is limited to the subendocardial myocardium and is smaller and less extensive than an ST-segment MI, and usually there is no pathologic Q wave on the ECG.

Nonalcoholic fatty liver disease (NAFLD): Refers to a wide spectrum of liver disease ranging from simple fatty liver (steatosis), to nonalcoholic steatohepatitis (NASH), to cirrhosis (irreversible, advanced scarring of the liver). All of the stages of NAFLD have in common the accumulation of fatty infiltration in the liver cells.

Nonarteritic, anterior, ischemic optic neuropathy: A disorder caused by an acute decrease of blood flow to the optic nerve, which results in sudden vision loss. If persistent, it can lead to permanent vision loss.

Nonconvulsive status epilepticus (NCSE): Believed to be less common and have a better prognosis than GCSE. The most common two types are absence status epilepticus and complex partial status epilepticus. Both are associated with an impairment in consciousness. For the more common of the two, absence status, the patient appears in a twilight state to lethargy, there is no return to consciousness as occurs in complex partial status epilepticus. For complex partial status epilepticus partial return to consciousness can occur. It may or may not be associated with motor activity or automatisms. The duration is sufficient enough in length to meet the definition of status epilepticus.

Nonoliguria: Production of >500 mL urine/day.

Nonpolyposis: Absence of polyps.

Nonulcer dyspepsia: Ulcer-like dyspepsia that has been investigated, but endoscopic findings yield no evidence of mucosal injury (ulcer).

Norepinephrine (NE): A hormone secreted by the adrenal medulla and also released at synapses.

Nosocomial infection: An infection acquired in a healthcare facility.

NSAID: Nonsteroidal antiinflammatory drug.

N-terminal proBNP: The biologically inactive fragment of B-type natriuretic peptide (BNP). Compared to BNP, N-terminal proBNP circulates at higher plasma concentrations and has a longer half-life.

Nulliparity: Condition of not having given birth to a child.

Obesity–hypoventilation syndrome: Also known as Pickwickian syndrome.

Oblique lie: The fetus is at an angle to the cervix. The head is not the presenting part, and often the patient will need to be delivered by cesarean section.

Obsession: Recurrent and persistent thoughts, images, or impulses experienced as intrusive and distressing.

Obsessive–compulsive disorder (OCD): An anxiety disorder characterized by obsessions and/or compulsions that are time-consuming and interfere significantly with normal routine, social or occupational functioning, or relationships.

Obstructive voiding symptoms: Decreased force of the urinary stream, hesitancy, incomplete bladder emptying, urinary dribbling. This results from bladder outlet obstruction as could be caused by benign prostatic hyperplasia.

Odynophagia: Painful swallowing.

Oligoanovulation: The condition of having few to no ovulatory menstrual cycles.

Oligomenorrhea: Reduced frequency of menses with a time interval between periods greater than 40 days but less than 6 months.

Oliguria: Production of <500 mL urine/day.

Omentumectomy: Excision of the double fold of peritoneum attached to the stomach and connecting it with abdominal viscera (omentum).

Onychomycosis: Fungal infection of the nail apparatus.

Open prostatectomy: In this surgical procedure, an enlarged prostate is removed in its entirety. Access to the prostate can be achieved by cutting through the bladder and reaching down to the prostate, or by cutting through the perineum (between the legs).

Ophthalmia neonatorum: Inflammation of the conjunctiva resulting from acquisition of gonococcal infection at birth.

Opioid addiction: A behavioral pattern manifesting as loss of control over opioid use, compulsive use, and continued use despite harm.

Opioid dependence: State that occurs subsequent to extended exposure to an opioid and manifests as withdrawal symptoms after abrupt dose reduction, discontinuation or after the administration of an opioid antagonist.

Opioid tolerance: Decreased effectiveness of opioid over time due to opioid exposure.

Opportunistic infection (OI): Infection with microorganism that occurs because of altered physiologic state of the patient.

Orchiectomy: The surgical removal of the testicles.

Organic erectile dysfunction: Term used to refer to erectile dysfunction that is caused by vascular, neurologic, and/or hormonal causes.

Orthopnea: Difficulty breathing after lying down.

Orthostatic hypotension: A significant drop in BP, defined as a SBP decrease of greater than 20 mm Hg or a DBP decrease of greater than 10 mm Hg, that occurs when changing from a supine to a standing position.

Osler nodes: Osler nodes are red, raised tender nodules usually 5 mm in diameter on the pulps of toes or fingers. Seen in patients with endocarditis, they are thought to be caused by the deposition of immune complexes.

Osteogenesis imperfecta: Genetic disorder characterized by low trabecular and cortical bone density.

Osteomalacia: Abnormal bone mineralization, referred to as rickets in children.

Osteomyelitis: Infection involving the bone.

Osteopenia: Low bone density, dual-energy x-ray absorptiometry (DXA) T-score of –1 to –2.5.

Osteophyte: A bony outgrowth or protuberance.

Osteoporosis: Very low bone density, DXA T-score less than –2.5, with or without a low trauma fracture. National Osteoporosis Foundation definition: “A chronic, progressive disease characterized by low bone mass, microarchitectural deterioration and decreased bone strength, bone fragility and a consequent increase in fracture risk.”

Osteotomy: The surgical cutting of a bone.

Otitis media: Inflammation of the middle ear.

Ovarian ablation: Removal or irradiation of the ovaries, rendering them nonfunctional.

Ovarian suppression: Medical castration in women through the use of medications.

Ovulation: Periodic ripening and rupture of mature follicle and the discharge of ovum from the cortex of the ovary.

Oxytocin: A polypeptide hormone secreted by the posterior pituitary gland that stimulates uterine contraction.

Paget’s disease: Disorder of bone remodeling in discrete sections of bone; also a disorder of the breast (primarily nipple complex) associated with breast cancer and/or bone changes.

PAH: p-Aminohippurate, a small molecule that is completely secreted from the tubules into urine, so that blood leaving the kidney is virtually free of PAH; a marker that is often used to measure renal plasma flow (RPF).

Pain: An unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage.

Palpation: Touching the skin to feel the outline of an organ.

Pan- or holosystolic: Throughout the end time of systole.

Pancolitis: Inflammation that involves the majority of the colon for patients with inflammatory bowel disease.

Pancreatitis: An acute or chronic inflammation of the pancreas with variable involvement of local tissues and remote organs.

Panel reactive antibody (PRA): The percentage of cells from a panel of donors with which a potential recipient’s bloodstream reacts. The more antibodies in the recipient’s bloodstream, the higher the PRA. The higher the PRA, the higher the risk for a positive crossmatch.

Panhypopituitarism: A condition of complete or partial loss of anterior and posterior pituitary function resulting in a complex disorder characterized by multiple pituitary-hormone deficiencies.

Panic attack: A discrete period in which there is the sudden onset of intense apprehension, fearfulness, or terror, often associated with feelings of impending doom.

Panic disorder: The presence of recurrent, unexpected panic attacks followed by at least 1 month of persistent concern about having another panic attack, worry about the possible implications or consequences of the panic attacks, or a significant behavioral change related to the attacks.

Panlobular: Affecting the entire lobe.

Papillary: Upper layer of the dermis.

Papilledema: Swelling around the optic nerve, usually caused by pressure on the nerve by a tumor or stroke.

Papule: Solid, elevated, lesion more than 0.5 cm in diameter.

Papules: Small raised bumps that may open when scratched and become crusty and infected.

Papulosquamous: Raised plaque or papule with scaling.

p-Aminohippurate (PAH): A small molecule that is completely secreted from the tubules into urine, so that blood leaving the kidney is virtually free of PAH; a marker that is often used to measure renal plasma flow (RPF).

Paranoia: Ideation involving suspiciousness or the belief that one is being harassed, persecuted, or unfairly treated.

Parenchyma: Specific cells or tissue of an organ.

Parenteral nutrition: The intravenous administration of nutrients.

Paresthesia: An abnormal sensation, such as burning, pricking, tickling, or tingling.

Peripherally inserted central catheter (PICC): A venous access device usually inserted into the basilic, cephalic, or brachial veins that terminates at the superior vena cava.

Peripheral parenteral nutrition: Parenteral nutrition delivered into a peripheral vein, usually of the hand or forearm.

Parkinsonism: A constellation of symptoms with atypical features such that a diagnosis of idiopathic Parkinson disease cannot be made.

Parous: Having borne one or more children.

Paroxysmal nocturnal dyspnea: Onset of difficulty breathing after lying down for several hours.

Partial agonist: A drug with high binding affinity to a receptor that elicits a weaker response than the endogenous neurotransmitter. At least theoretically, this causes an agonist effect in states of decreased endogenous neurotransmitter tone and an antagonist effect in the endogenous state of heightened neurotransmitter activity.

Partial seizure: A seizure that begins in one hemisphere of the brain. It can be simple, complex, or secondarily generalized.

Patch: Large macule (more than 2 cm in diameter).

Patient-reported outcomes: The consequences of the disease and/or its treatment as perceived and reported by the patient.

Pelvic inflammatory disease (PID): Infection of the lining of the uterus, the fallopian tubes, or the ovaries.

Penumbra (ischemic): The area of brain tissue around the core of the infarct that has decreased function but remains viable. It is proposed that reperfusion of this tissue will allow survival of the affected neurons and other brain cells.

Peptic ulcer: Cellular distribution of the gastrointestinal mucosa, submucosa, and muscular layer. Chronic peptic ulcers usually occur as a “single hole” and are found most often in the stomach and duodenum.

Percussion: Tapping on a structure to elicit a sound.

Percussion and postural drainage: Tapping on the thorax to physically loosen pulmonary secretions and posturing the body to facilitate expectoration.

Percutaneous coronary intervention (PCI): A minimally invasive procedure whereby access to the coronary arteries is obtained through the femoral artery up the aorta to the coronary os. Contrast media is used to visualize the coronary artery stenosis using a coronary angiogram. A guidewire is used to cross the stenosis and a small balloon is inflated and/or stent is deployed to break up atherosclerotic plaque and restore coronary artery blood flow. The stent is left in place to prevent acute closure and restenosis of the coronary artery. Newer stents are coated with antiproliferative drugs, such as paclitaxel and sirolimus, which further reduce the risk of restenosis of the coronary artery.

Pericarditis: Inflammation of the pericardium, which is the fibroserous sac enclosing the heart.

Perimenopause: The period immediately prior to the menopause and the first year after menopause. Reflects the transition to menopause (with irregular menstrual cycles) and includes the 3 to 5 years before and 1 year after the cessation of menstrual flow.

Perinatal: Time shortly before and after birth.

Periodontitis: A serious gum infection caused by inflammation and infection of the ligaments that support the teeth.

Perioral dermatitis: Rash around the mouth. In patients with anorexia nervosa or bulimia nervosa, the rash is secondary to repeated vomiting that creates skin irritation from exposure to the gastric contents.

Peripheral arterial disease (PAD): Atherosclerotic occlusive disease of the extremities, usually diagnosed by symptoms (claudication) or assessment of the blood flow to an extremity.

Peripheral blood progenitor cells: Immature blood cells, which are capable of producing white blood cells, platelets, and red blood cells.

Peritoneal dialysis (PD): A dialysis procedure performed in the peritoneal cavity in which the peritoneum acts as the semipermeable membrane.

Peritonitis: The acute, inflammatory response of the peritoneal lining to microorganisms, chemicals, irradiation, or foreign body injury.

Periungual pyogenic granulomas: Benign vascular lesion around the fingernails or toenails; can relate to acitretin use.

Perseveration: Persistent repetition of the same verbal or motor response despite differing stimuli.

Pervasive developmental disorder: A group of disorders described in the DSM-IV-TR characterized by severe and pervasive impairments in the development of socialization and communication skills, as well as behavioral repertoire, with a typical diagnosis younger than age 3 years; includes autistic disorder, Rett syndrome, pervasive development disorder not otherwise specified, childhood disintegrative disorder, and Asperger disorder. The term pervasive developmental disorder is not used in the DSM-5.

Petechiae: Pinpoint, flat, round, red spots under the skin caused by intradermal hemorrhage.

Peyronie’s disease: Disease of the penis associated with fibrous tissue scarring along the inside of the penile shaft resulting in significant and abnormal curvature of the erect penis. Associated with penile pain; deformity makes sexual intercourse difficult or impossible.

P-glycoprotein: An adenosine triphosphatase (ATPase)-dependent membrane transporter efflux pump coded for by the multidrug-resistance gene 1 (MDR1 or ABCB1 or PGY1) found in the human blood-brain barrier and intestine as well as other tissues; lipophilic molecules are good substrates for the ABCB1 efflux transport system at the blood–brain barrier.

Pharmacodynamics: The study of the relationship between the concentration of a drug and the response obtained in a patient.

Pharmacoepidemiology: The study of the use of and the effects of drugs in large numbers of people with the purpose of supporting safe and effective drug therapies. This type of observational research is useful when more rigorous, experimental designs are not feasible.

Pharmacogenetics: Genetic basis for interindividual differences in drug response.

Pharmacovigilance: The science and activities relating to the detection, assessment, understanding, and prevention of adverse effects or any other drug-related problems.

Pharyngitis: An acute infection of the oropharynx or nasopharynx.

Phase I reactions: Metabolic changes by the body that generally make the drug molecule more polar and water soluble so that it is prone to elimination by the kidney, such as oxidation, hydrolysis, and reduction.

Phase II reactions: Metabolic changes by the body that generally make the drug molecule more prone to elimination by the kidney, such as conjugation to form glucuronides, acetates, or sulfates.

Phenotype: Outward expression of the genotype.

Phenotypes: How a gene is expressed (e.g., eye color, height, drug metabolism capacity). The expression of genetic alleles (genotype) as an observable physical or biochemical trait.

Phobia: A persistent, abnormal, and irrational fear of a specific thing or situation that compels one to avoid it, despite the awareness and reassurance that it is not dangerous.

Phonophobia: Hypersensitivity to sound, usually causing avoidance.

Photic stimulation: Stimulation of the visual cortex through visual stimulation with bright and alternating light.

Photoallergy: Photosensitivity disorder of skin (light and photoallergic agent).

Photophobia: Hypersensitivity to light, usually causing avoidance.

Phototoxicity: Photosensitivity disorder of skin (light and phototoxic agent).

Physical dependence: A state of adaptation that is manifested by a drug class–specific withdrawal syndrome that can be produced by abrupt cessation, rapid dose reduction, decreasing blood level of the drug, and/or administration of an antagonist.

Pickwickian syndrome: Excess load of excess body fat on the chest tissues resulting in a constellation of syndromes that include excessive daytime sleepiness, shortness of breath due to elevated blood carbon dioxide pressure, disturbed sleep at night, and flushed face.

Pilonidal: Hair-containing cyst.

Pilosebaceous: Sebaceous gland and adjacent hair follicle.

Placenta accreta: Attachment of placental villi to the muscle of the uterine wall causing abnormally firm placental adherence. Complications include intractable postpartum hemorrhage.

Placenta previa: Placental implantation at or near the opening of the cervix. Severe maternal hemorrhage can occur because the placenta precedes the infant during birth.

Plantar fasciitis: A condition that causes heel and arch pain as a result of irritation and inflammation of the plantar fascia, the connective tissues that form the arch of the foot.

Plaque: Raised, flat lesion (more than 2 cm in diameter).

Pneumonitis: Inflammation of lung tissue.

Podagra: Intense pain in the foot, often in the great toe as a symptom of gout.

Poikilocytosis: The presence of irregularly shaped red blood cells in the peripheral blood.

Poikilothermia: Inability to maintain normal body temperature.

Polyarteritis nodosa: A systemic necrotizing vasculitis of small and medium-sized arteries.

Polycystic ovarian syndrome: An endocrine disorder with a constellation of symptoms with excessive androgen activity, including irregular or no menstrual periods, acne, excessive hair growth, and infertility.

Polycythemia: An increase in the number of red cells present in the blood.

Polymorphism: Genetic variations occurring at a frequency of at least one percent in the human population.

Porphyria: A group of disorders involving heme biosynthesis, characterized by excessive excretion of porphyrins or their precursors; can be inherited or can be acquired, as from the effects of certain chemical agents.

Porphyrins: Pigments widely distributed throughout nature (e.g., heme, bile pigments, cytochromes) consisting of four pyrroles joined in a ring (porphin) structure.

Positive symptoms: Those symptoms of schizophrenia, largely based on perceptual and thought disturbances, that are typically associated with psychosis. Examples are suspiciousness, paranoia, delusions, hallucinations, and disorganized thought processes.

Positron emission tomography (PET): Specialized nuclear scanning technique that allows the measurement of regional blood flow and glucose metabolism. With radiolabeled ligands, it also allows for the measurement of the binding of drugs to receptors.

Posterior fossa: The cavity in the back part of the skull that contains the cerebellum, brainstem, and cranial nerves 5–12.

Postexposure prophylaxis: Dispensing or administering a medication (including a vaccine) to start immediately after exposure to a disease or organism, to prevent the disease from developing or spreading.

Postictal: The recovery period after a seizure, when a patient can be lethargic or confused. Duration can be variable.

Posttraumatic seizures: Seizure event(s) that can occur following a traumatic brain injury within the first 7 days postinjury (early) or beyond 7 days postinjury (late).

Posttraumatic stress disorder: An anxiety disorder in which exposure to an exceptional mental or physical stressor is followed by persistent reexperiencing of the event, avoidance of reminders of the event, and arousal symptoms.

Postvoid residual urine volume: Urine left in the bladder after the patient has been asked to completely empty urine out of the bladder. Normally, the postvoid residual urine volume should be zero. A high postvoid residual urine volume is associated with recurrent urinary tract infection.

PRA (panel reactive antibody): The percentage of cells from a panel of donors with which a potential recipient’s bloodstream reacts. The more antibodies in the recipient’s bloodstream, the higher the PRA. The higher the PRA, the higher the risk for a positive crossmatch.

Preexposure vaccination: Administration of a protective vaccine to the public, military troops, or high-risk individuals prior to the potential exposure to an infectious disease.

Preference-based measures: Measures that provide an overall HRQOL index score based on a scale anchored by 1.0 (full health) and 0.0 (dead).

Prefrontal cortex: Part of the brain that integrates thought, emotion, and motivation.

Preload: Along with afterload, it is an important determinant of cardiac output. It is the degree of stretch of the myocardial fibers (sarcomeres) at the end of diastole. As the sarcomeres are stretched, the force of contraction increases. Preload is approximated by the left ventricular end diastolic volume or pressure.

Premature infants: Those born before 37 weeks of gestational age.

Premature ovarian failure: Amenorrhea, sex-steroid deficiency, and infertility in women younger than 40 years of age.

Premenstrual dysphoric disorder (PMDD): Severe psychiatric mood disorder with marked affective symptoms causing significant interference in work or relationships temporally associated with the final week before the onset of menses and not caused by an underlying psychiatric disturbance. The diagnostic criteria require prospective documentation of symptoms, a specific constellation of symptoms, and functional impairment.

Premenstrual molimina: Includes premenstrual symptoms such as breast tenderness, pelvic heaviness or bloating, and food cravings that are not distressing and do not interfere with daily functioning.

Premenstrual syndrome (PMS): A constellation of symptoms including mild mood disturbance and physical symptoms that occur prior to the menses and resolve with initiation of menses.

Premonitory migraine symptoms: Symptoms preceding and forewarning of a migraine attack by 2 to 48 hours, occurring before the aura in migraine with aura and before the onset of pain in migraine without aura.

Presbycusis: Progressive bilateral loss of hearing that occurs in the aged.

Pressured speech: More and faster speech that is difficult or impossible to interrupt.

Preterm: Before 37 weeks of gestation.

Priapism: Painful prolonged erection.

Primary amenorrhea: Absence of menses by age 16 years in the presence of normal secondary sexual development or absence of menses by age 14 years in the absence of normal secondary sexual development.

Primary hypertension: Same as essential hypertension; persistently elevated BP that results from unknown pathophysiological etiology.

Primary hypogonadism: Failure of the testes to produce an adequate supply of testosterone to meet physiologic needs.

Primary lesion: Basic skin lesion that appears at the beginning of skin disorder.

Primary resistance: Refers to resistance recorded prior to drug exposure in vitro or in vivo, as determined by in-vitro susceptibility testing using standardized methodology.

Proctitis: Inflammation confined to the rectum for patients with inflammatory bowel disease.

Prodrome: Early symptom indicating that disease or further symptoms are imminent.

Progestins: Formulations of synthetic progesterone.

Progestogen: A term referring to progesterone and the synthetic progestational compounds (sometimes referred to as progestins).

Progressive multifocal leukoencephalopathy (PML): Rapidly progressive neuromuscular disease caused by opportunistic infection of brain cells by the JC virus.

Prolactin: A polypeptide hormone secreted by the anterior pituitary gland that stimulates lactation.

Proprioception: A sense or perception, usually at a subconscious level, of the movements and position of the body and especially its limbs, independent of vision; this sense is gained primarily from input from sensory nerve terminals in muscles and tendons and the fibrous capsule of joints combined with input from the vestibular apparatus.

Prostate-specific antigen (PSA): A clinical laboratory test; PSA is a tumor marker that is used to screen for, monitor response to treatment of, and determine degree of spread of prostate cancer. Normally, PSA blood levels should be low as PSA is passed out of the body in the ejaculate.

Prostatectomy: Removal of all or part of the prostate gland. There are two main types: (1) transurethral resection of the prostate (TURP)—removes part of the tissue surrounding the urethra that can be blocking the flow of urine; and (2) radical prostatectomy, which removes all of the prostate and the seminal vesicles.

Protease: An enzyme in HIV that cleaves large precursor polypeptides into functional proteins that are necessary to produce a complete virus.

Proteinuria: A condition in which the urine contains large amounts of protein (>150 mg/day); often a sign of glomerular or tubular damage in the kidney.

Proteolytic: The ability to break down protein.

Prothrombin: A clotting factor that is converted to thrombin; also known as factor II.

Prothrombin time (PT): A measure of coagulation representing the amount of time required to form a blood clot after the addition of thromboplastin to the blood sample; also known as Quick’s test.

Pruritus: Itching.

Pseudoaddiction: A behavior pattern reflective of seeking relief of pain and resembling that of addictive behavior.

Pseudoallergic: Adverse reactions that appear like allergic reactions but do not have an immunologic mechanism.

Pseudocyst: Collection of pancreatic juice and tissue debris enclosed by a wall of fibrous or granulation tissue.

Pseudohypertension: A falsely elevated BP measurement that is usually because of rigid, calcified brachial arteries; this can be seen in patients who are elderly, have longstanding diabetes, or have chronic kidney disease.

Pseudomembranous colitis: Inflammation of the colon caused by the toxin of Clostridium difficile and resulting in bloody diarrhea.

Pseudopolyps: An area of hypertrophied gastrointestinal mucosa that resembles a polyp and contains nonmalignant cells.

Pseudotumor cerebri: Increased intracranial pressure caused by decreased venous drainage from the brain as a result of increased intraabdominal pressure. Symptoms usually include severe headache, bilateral pulsatile auditory tinnitus, and visual field cuts. Also known as idiopathic intracranial hypertension.

Pseudoxanthoma elasticum: Pseudoxanthoma elasticum is a chronic degenerative disease of connection tissues of the skin, eyes, and cardiovascular system resulting from fragmentation and calcification of elastic fibers.

Psoriasis: A chronic, noncontagious autoimmune disease that affects the skin in the form of thick, red, scaly patches.

Psychoeducation: Education geared toward patients becoming more informed about their mental illness and treatment. Additional goals include self-monitoring, efforts to improve treatment adherence, interactions between patient and clinicians, and empowerment.

Psychogenic erectile dysfunction: Erectile dysfunction because of failure of central nervous system to perceive or process sexually stimulating information.

Psychometrics: The measurement of psychologic constructs, such as quality of life.

Psychomotor: Movement or muscular activity related to mental processes.

Psychomotor retardation: A slowing or limitation of motor functioning or muscular movements.

Psychosocial functioning: A person’s level of functioning on a daily basis that encompasses all the domains of life experience (e.g., interpersonal relationships, work, school, recreation).

Psychosocial rehabilitation programs: Care programs oriented toward improving patient’s daily adaptive functioning. Includes such interventions as basic living skills, social skills training, basic education, work programs, and supported housing.

Psychosocial stressor: Any significant life event or change that can be associated with the onset, occurrence, or exacerbation of a mental disorder.

Psychotherapy: A general term used to describe a form of treatment based on talking with a therapist. Psychotherapy aims to relieve distress by discussing and expressing feelings, to help the patient to change attitudes, behavior, and habits and to develop better ways of coping.

Pulmonary artery occlusion pressure: It is usually determined by a balloon-tipped Swan-Ganz catheter that is advanced into a distal branch of the pulmonary artery. Inflation of the balloon at the catheter tip occludes the pulmonary artery and allows measurement of the left atrial pressure which reflects the left ventricular diastolic pressure. Therefore, it is a measure of the left ventricular preload.

Pulmonary aspiration: The inhalation of fluids and gastric contents into the lungs that can cause aspiration pneumonitis.

Pulmonary capillary wedge pressure: It is usually determined by a balloon-tipped Swan-Ganz catheter that is advanced into a distal branch of the pulmonary artery (PA). Inflation of the balloon at the catheter tip occludes the PA and allows measurement of the left atrial pressure which reflects the left ventricular diastolic pressure. Therefore, it is a measure of the left ventricular preload.

Pulmonary embolism: A disorder of thrombus formation causing obstruction of a pulmonary artery or one of its branches and results in pulmonary infarction.

Pulsating: Throbbing or beating with a rhythm.

Pulseless electrical activity: The absence of a detectable pulse and the presence of some type of electrical activity other than VF or PVT.

Purgatives: An agent used for purging the bowels.

Purpura: Discoloration of skin because of a hemorrhagic spot more than 0.5 cm in diameter.

Pustule: Small, raised lesion containing pus or exudates.

Pyelonephritis: An infection involving the kidneys and representing upper tract infection.

Pyoderma: Purulent skin disease.

Pyoderma gangrenosum: Skin ulceration with necrotic edges.

Pyuria: Presence of pus or white blood cells in the urine.

Quality-adjusted life-years (QALY): A health outcome summary measure in which quantity of life is adjusted for its quality. A year in full health is equivalent to 1.0 QALY. A year in a health state considered worse than full health, such as 0.5, would equal 0.5 QALY, which is equivalent to living half a year in full health.

Radionuclide ventriculography: Radionuclide ventriculography, also known as contrast ventriculography, provides imaging of a ventricle of the heart after the injection of a radioactive contrast medium. The technique is less invasive than cardiac catheterization and is used to assess ventricular function.

Rales: The clicking, rattling, or crackling noises heard on auscultation of the lungs during inhalation.

Rating scales: Tools used to objectively describe, assess, and measure subjective findings common in psychiatric illnesses. Rating scales are also used to diagnose specific psychiatric conditions.

Rational polytherapy: The concurrent use of two or more drugs for patients not responding to monotherapy. The combination of drugs is based on a consideration of mechanism of action, clinical pharmacokinetics, adverse reactions, and drug interactions.

Rebound insomnia: Sleep that is worsened compared with patient’s baseline sleep for a few days after discontinuation of a sedative hypnotic medication.

Rebound vasodilation or congestion: See Rhinitis medicamentosa.

Refractory status epilepticus: Status epilepticus is considered refractory when adequate doses of a benzodiazepine, hydantoin, or barbiturate have failed to terminate the seizures, that is, a patient must have failed two first line therapies to be considered refractory.

Rejection: The response of the immune system, usually involving T- or B-lymphocytes, to the recognition of foreign antigens in transplanted tissue, which destroys the cells in the transplanted organ and ultimately leads to organ failure, if not treated successfully.

Relapse in multiple sclerosis: New or old multiple sclerosis symptoms lasting 24 hours or longer often associated with demyelination or inflammation in the brain or spinal cord. Relapses are also referred to as an attack, exacerbation, or flare-up of multiple sclerosis.

Relapsing-remitting multiple sclerosis: The most common form of multiple sclerosis at the time of diagnosis. It is characterized by attacks usually with full or partial recovery and no disease progression between attacks.

Relative risk reduction: The amount of risk reduced when compared to a control. When one sees a 5% event rate in the control group and a 4% event rate in the treatment group, the relative risk reduction is 20%. The absolute risk reduction is 1%.

Reliability: The extent to which measures give consistent or accurate results.

Remote symptomatic: When the cause of the status epilepticus is from a previous neurological injury or anatomical malformation, e.g., a patient with a prior stroke, head trauma or brain tumor.

Renal osteodystrophy (ROD): The condition resulting from sustained metabolic changes that occur with chronic kidney disease including secondary hyperparathyroidism, hyperphosphatemia, hypocalcemia, and vitamin D deficiency. The skeletal complications associated with ROD include osteitis fibrosa cystica (high bone turnover disease), osteomalacia (low bone turnover disease), adynamic bone disease, and mixed bone disorders.

Renal replacement therapy: Any form of dialysis or hemofiltration used to support patients without adequate kidney function. Goals of renal replacement therapy are to remove excess fluid; remove waste products and toxins; and control electrolyte concentrations.

Renal: General term referring to the kidneys.

Renin-angiotensin-aldosterone system: A complex endogenous humoral mediated system that is involved with most of the regulatory components involved with arterial BP.

Renovascular: Pertaining to blood vessels located within the kidney, such as the afferent and efferent arterioles, and renal arteries.

Resistant hypertension: Patients with hypertension who have not achieved their goal BP value despite treatment with three or more antihypertensive drugs.

Respiratory disturbance index: A summary measure that quantifies the number of apneas, hypopneas, and respiratory effort-related arousals per hour of sleep.

Respondent burden: The time, energy, and other demands placed on those to whom the instrument is administered.

Responsiveness: The ability or power of a measure to detect clinically important change when it occurs.

Resting tremor: Tremor that occurs or exacerbates when the affected body part is at rest; it decreases or disappears with active motions.

Restrictive cardiomyopathy: Restrictive cardiomyopathy is characterized by nondilated ventricles with impaired ventricular filling. Hypertrophy is typically absent, although the infiltrative and storage diseases can cause a left ventricular wall thickness elevation.

Retching: Contractions of the diaphragm, thoracic, and abdominal muscles without expulsion of gastric contents.

Retinitis: Inflammation of the retina, often caused by infection with cytomegalovirus.

Retinoid dermatitis: Erythematous scaly patches with superficial skin fissuring.

Retrograde pyelography: A procedure where radiocontrast dye is injected into the ureter to produce detailed radiographs of the ureter and kidneys.

Rett’s syndrome: A type of pervasive developmental disorder (DSM-IV) typically associated with severe to profound mental retardation, seen in females only, with the development of significant multiple progressively worsening deficits following a period of normal development (microcephaly, loss of purposeful hand motor skills, and acquisition of stereotyped hand movements, diminished social interests, and appearance of poorly coordinated gait or trunk movements). This disorder falls within Austism Spectrum Disorder in the DSM-5.

Reverse transcriptase: The enzyme in HIV that synthesizes a complementary strand of DNA.

Reversible posterior leukoencephalopathy syndrome (RPLS): Rare, life-threatening condition affecting the brain. Symptoms include headaches, seizures, confusion, and vision problems. Prognosis good with early identification and treatment.

Reye’s syndrome: Acute encephalopathy characterized by fever, vomiting, fatty infiltration of the liver, disorientation, and coma, occurring mainly in children and usually following a viral infection, such as chicken pox or influenza.

Rhabdomyolysis: The breakdown of muscle tissue and release of myoglobin and intracellular electrolytes into the circulation because of a variety of causes such as crush injuries, drug-induced immobilization, and status epilepticus. It often leads to acute renal failure.

Rheumatoid arthritis: A systemic, symmetric autoimmune disease with swelling, pain, and inflammation of joints as a key finding.

Rhinitis: Inflammation of the nasal mucous membrane. Can be seasonal (hay fever) or perennial (increasingly called intermittent or persistent).

Rhinitis medicamentosa: Nasal congestion associated with tolerance to and resulting overuse of topical decongestants. Also known as rebound vasodilation or rebound congestion.

Rickets: See Osteomalacia.

Rigidity: Increased resistance detectable with the passive movement of a limb.

Roth spots: A hemorrhage in the retina with a white center. Roth spots are often associated with bacterial endocarditis.

Russell sign: Callus on dorsum of the hand secondary to self-induced vomiting.

S4gallop: An S4 gallop is a presystolic atrial sound that immediately precedes the first heart sound (S1). This finding on auscultation of the heart can be indicative of myocardial disease.

Salicylism: Poisoning by salicylic acid or any of its compounds.

Salpingo-oophorectomy: Surgical removal of the ovaries and fallopian tubes.

Sarcoidosis: Sarcoidosis is a multisystem granulomatous disorder of unknown etiology characterized histologically by noncaseating epithelioid granulomas involving various organs or tissues, with symptoms dependent on the site and degree of involvement.

Scale: Flake of stratum corneum.

Scar: Fibrous tissue formed during healing of injury to skin.

Schizophrenia: A chronic disorder of thought and affect encompassing different constellations of symptoms (i.e., positive symptoms, negative symptoms, cognitive dysfunction), with the individual having a significant disturbance in interpersonal relationships and ability to function in society on a daily basis.

Scleritis: Inflammation of the white portion of the eyeball, which can be superficial (episcleritis) or involve deeper layers of the eye.

Scleroderma: Scleroderma is a diffuse connective tissue disease characterized by changes in the skin, blood vessels, skeletal muscles, and internal organs.

Sebaceous gland: Gland that secretes sebum.

Sebosuppressive: Decreasing amount of sebum produced by the sebaceous gland.

Sebum: Oil produced by the sebaceous gland.

Second-degree relative (SDR): A blood relative, including the individual’s grandparents, grandchildren, aunts, uncles, nephews, nieces, and half-siblings.

Second-generation antipsychotic (atypical antipsychotic): An antipsychotic medication that has pharmacodynamic and clinical properties different than the first generation (typical or traditional) antipsychotics that act primarily by having high levels of binding to dopamine-2 (D2) receptors. Although definitions of atypicality vary, all second-generation antipsychotics share the property of causing a much lower incidence of extrapyramidal side effects.

Secondary amenorrhea: Cessation of menses in a woman previously menstruating for 6 months or more.

Secondary brain injury: A complex sequence of pathophysiologic events precipitated by the initial or primary brain injury that disrupts the normal central nervous system balance between oxygen supply and demand resulting in a worsened patient outcome.

Secondary hypertension: Persistently elevated BP that results from a known pathophysiological etiology or drug-induced cause.

Secondary hypogonadism: Failure of hypothalamus or pituitary gland to produce adequate amount of luteinizing hormone-releasing hormone (LHRH) or luteinizing hormone (LH). Thus, testicular production of testosterone is reduced.

Secondary prophylaxis (or suppressive therapy): Refers to administration of systemic antifungal agents (generally prior to and throughout the period of granulocytopenia) to prevent relapse of a documented invasive fungal infection that was treated during a previous episode of granulocytopenia.

Secondary resistance: Develops on exposure to an antifungal agent and can be either reversible, because of transient adaptation, or acquired as a result of one or more genetic alterations.

Secondary-progressive multiple sclerosis: Often follows relapsing-remitting multiple sclerosis whereby attacks become continuously progressive over time. It is sometimes accompanied by acute relapses.

Seizure: Paroxysmal disorder of central nervous system, characterized by abnormal neuronal discharges with or without loss of consciousness. They vary in cause, presentation, consequences, duration, and management.

Selection bias: Systematic differences in characteristics between those selected for study and those who are not. See also Information bias.

Sepsis: The systemic inflammatory response syndrome (SIRS) secondary to infection. See also Systemic inflammatory response syndrome.

Septic arthritis: Infection involving a joint.

Septic shock: Sepsis with persistent hypotension despite fluid resuscitation, along with the presence of perfusion abnormalities. Patients who are on inotropic or vasopressor agents might not be hypotensive at the time perfusion abnormalities are measured.

Serotonin (5-hydroxytryptamine [5-HT]): An inhibitory neurotransmitter present in the raphe nucleus of the brainstem, platelets, carcinoid tumors, and other tissues. It is a vasoconstrictor and neurochemical involved in mood and sleep.

Serum urea nitrogen (SUN): See Blood urea nitrogen.

Severe sepsis: Sepsis associated with organ dysfunction, hypoperfusion, or hypotension. Hypoperfusion and perfusion abnormalities can include, but are not limited to, lactic acidosis, oliguria, or acute alteration in mental status.

Short stature: A broad term describing a condition commonly defined by a physical height that is more than two standard deviations below the population mean and lower than the third percentile for height in a specific age group.

Sickle cell disease: A group of inherited red blood cell (RBC) disorder in which sickle cell hemoglobin (HbS) is present. Hemolytic anemia and painful vasoocclusion are the main features.

Simple partial seizure: A seizure beginning in one hemisphere of the brain. It is manifested by alterations in motor functions, sensory or somatosensory symptoms without loss of consciousness. It can progress to a complex partial seizure or to a secondarily generalized seizure with loss of consciousness.

Single-nephron GFR (SNGFR): The rate of filtration through a single glomerulus of a nephron; often reported in nL/min.

Sinus ostia: The pathways that drain the sinuses.

Sinusitis: An inflammation and/or infection of the paranasal sinus mucosa.

Sjögren’s syndrome: An inflammatory process affecting the mucous membranes. Can cause dry mouth with difficulty swallowing. Can occur secondary to autoimmune diseases such as rheumatoid arthritis or systemic lupus erythematosus.

Sleep latency: The amount of time it takes to fall asleep.

Sleep spindles: Brief burst of electrical activity seen on the EEG, 12 to 14 Hz.

Slipped capital femoral epiphysis (SCFE): Increased width of the femoral plate observed during GH treatment resulting in hip or knee pain.

Social anxiety disorder (SAD): A disorder characterized by clinically significant anxiety provoked by exposure to certain types of social or performance situations, often leading to avoidance behavior.

Social determinants of health: Include the socioeconomic, culture, and environmental conditions as well as social and family networks that influence individual health.

Social phobia: See Social anxiety disorder.

Somatic pain: Pain arising from skin, bone, joint, muscle, or connective tissue.

Specific measures: Instruments intended to provide greater detail concerning particular outcomes, in terms of functioning and well-being, uniquely associated with a condition and/or its treatment.

Specific phobia: A phobia characterized by clinically significant anxiety provoked by exposure to a specific feared object or situation, often leading to avoidance behavior.

Spermicide: A substance (nonoxynol-9 in the United States) placed in the vagina to inhibit the activity of sperm, thus reducing the risk of pregnancy; available as vaginal creams, films, foams, gels, suppositories, sponges, and tablets.

Spiculated: With spikes or points on the surface.

Spirochete: The class of microorganism that is the agent of syphilis (Treponema pallidum).

ST-segment elevation: A type of myocardial infarction that typically results in an injury that transects the thickness of the myocardial wall. Following an ST-elevation MI, pathologic Q waves are frequently seen on the ECG, indicating transmural myocardial infarction.

Standard gamble: An approach to health-state preference elicitation in which the respondent is offered a choice between two alternatives: choice A—living in health state i (a health state between full health and death) with certainty, or choice B—taking a gamble on a new treatment for which the outcome is uncertain.

Status epilepticus: Defined as any recurrent or continuous seizure activity lasting longer than 30 minutes in which the patient does not regain baseline mental status. The two most common types are generalized convulsive status epilepticus and nonconvulsive status epilepticus.

Steatorrhea: Excessive fat in stool.

Stereotypy: Persistent repetition of senseless acts or words.

Stevens–Johnson syndrome: A serious dermatologic reaction characterized by blistering of the mucous membranes (mouth, eyes, vagina) with patchy rashes that can cover most of the body. Patients can also experience fever, headache, and cough.

Stress-related mucosal damage: Superficial gastritis-like lesions associated with critical illness in hospitalized patients.

Striae: Linear, atrophic, pink, purple, or white lesions of skin secondary to changes in connective tissue.

Stricture: An area of narrowing or constriction in the gastrointestinal tract due to buildup of fibrotic tissue; often a result of longstanding inflammation.

Stroke: A sudden onset, focal neurologic deficit, of presumed vascular origin, lasting longer than 24 hours.

Stroke volume: The volume of blood ejected from the heart during systole.

Stromal tissue of the prostate: This portion of the prostate is composed of smooth muscle tissue, which is embedded with α-adrenergic receptors. When stimulated, the muscle contracts around the urethra. This comprises approximately 75% of the total volume of the enlarged prostate gland in patients with benign prostatic hyperplasia.

Subarachnoid hemorrhage: Accumulation of blood in the space (subarachnoid space) surrounding the brain that usually contains the cerebrospinal fluid. It is usually caused by rupture of an intracranial aneurysm or trauma. It is a type of hemorrhagic stroke and can cause focal neurologic deficits.

Substance abuse: A maladaptive pattern of substance use indicated by repeated adverse consequences related to the repeated use of the substance. Examples include failure to fulfill important obligations at work, school, or home; repeated use in situations in which it is physically dangerous, such as driving under the influence; legal problems; and social or interpersonal problems such as arguments and fights.

Substance dependence: A state of adaptation that is manifested by a drug class-specific withdrawal syndrome that can be produced by abrupt cessation, rapid dose reduction, decreasing blood level of the drug, and/or administration of an antagonist. The continued use of the substance despite adverse substance-related problems.

Substantia nigra: Area of the brain (basal ganglia) where cells produce dopamine; characterized by neuromelanin deposits.

Subtle status epilepticus: For patients with prolonged refractory status epilepticus. The electrographical seizures persist; however, the motor manifestations of the seizures may not be apparent. In such cases the patient is considered in subtle status epilepticus.

Sudden death: Also known as sudden cardiac death; an unexpected death because of cardiac causes occurring in a short time period (generally within 1 hour of symptom onset) in a person with known or unknown cardiac disease in whom no previously diagnosed fatal condition is apparent. Most cases are related to cardiac arrhythmias, particularly ventricular fibrillation.

SUN (serum urea nitrogen): See Blood urea nitrogen.

Suppressive therapy: See Secondary prophylaxis.

Surge capacity: A term that refers to a healthcare system’s ability to handle a large influx of patients in the event of an epidemic or disaster.

SV2A: A presynaptic vesicle protein found in the hippocampus as well as other areas of the brain believed to be important in the mechanism of action of levetiracetam.

Swan–Ganz catheter: A catheter (tube) inserted into the heart to measure pressure and cardiac output.

Symptomatic intracerebral hemorrhage: Collection of blood in the brain, usually after an ischemic stroke, that is associated with neurologic worsening.

Symptomatic status epilepticus: Status epilepticus occurring during the time of an acute neurological injury. This etiology is associated with a poorer prognosis.

Systemic vascular resistance: The resistance to blood flow that is primarily determined by the vascular tone of the arteriolar blood vessels.

Syncope: Fainting.

Synechiae: A creeping angle closure that sometimes occurs in patients between attacks of closed-angle glaucoma.

Synergism: The combination of two drugs (such as antibiotics) that produces an effect greater than the sum of the two drugs if used alone.

Synesthesias: The overflow of one sensory modality to another. For example, colors are heard, sounds are seen.

Synovitis: Inflammation of the synovial lining of the joint.

Synovium: Synovial membrane, the inner of the two layers of the articular capsule of a synovial joint, composed of loose connective tissue and having a free smooth surface that lines the joint cavity. It secretes the synovial fluid.

Systemic inflammatory response syndrome (SIRS): Systemic inflammatory response to a variety of clinical insults, which can be of infectious or noninfectious etiology.

Systemic vascular resistance (SVR): The resistance to blood flow that is primarily determined by the vascular tone of the arteriolar blood vessels.

Systolic blood pressure: The arterial BP that occurs during cardiac contraction.

Systolic heart failure: Systolic heart failure is a condition characterized by a decrease in myocardial contractility, which results in a reduction in the cardiac output and left ventricular ejection fraction.

Tachy-brady syndrome: Tachy-brady syndrome, also known as sick sinus syndrome, is a condition in which the sinoatrial node is unable to perform as the pacemaker of the heart.

Tangential speech: Speech pattern whereby the connections between expressed ideas are unrelated or have little relationship to each other.

Taper: To gradually decrease the dosage of a drug over a period of time.

Tardive: A modifier used to describe movement disorders secondary to chronic antipsychotic treatment (duration of treatment must be greater than 3 months). The disorder must persist for greater than 4 weeks and exhibit masking and unmasking characteristics. Tardive dyskinesia, tardive chorea, tardive dystonia, and tardive akathisia are examples of tardive movement disorders.

Telangiectases: Spidery red skin lesions caused by dilated blood vessels.

Tendonitis: Inflammation of tendons.

Tenesmus: Difficulty with bowel evacuation despite the urgency to defecate.

Teratogenicity: Ability of an agent to cause a defect or malformation in a fetus.

TEWL (transepidermal water loss): The rate of water loss by evaporation from the skin.

Thalassemia: Any of a group of inherited disorders of hemoglobin metabolism in which there is impaired synthesis of one or more of the polypeptide chains of globin.

Third-spacing: The shift of fluid and protein into the peritoneal cavity and bowel wall lumen that occurs as a result of peritonitis.

Thought blocking: Interruption of a train of thought whereby the person stops speaking suddenly and without warning, even in the middle of a sentence. Person may report that the thoughts were taken out of his or her head.

Thought broadcasting: Belief that one’s thoughts are audible to others.

Thrombin: The enzyme formed from prothrombin that converts fibrinogen to fibrin. It is the principle driving force in the clotting cascade.

Thrombogenesis: The process of forming a blood clot.

Thrombolysis: The process of enzymatically dissolving or breaking apart a blood clot.

Thrombolytic: An enzyme that dissolves or breaks apart blood clots.

Thromboplastin: A substance that triggers the coagulation cascade. Tissue factor is a naturally occurring thromboplastin and used in the prothrombin time (PT) test.

Thrombopoiesis: The process of platelet production from immature cells.

Thrombosis: The process of forming a thrombus.

Thrombotic thrombocytopenic purpura: A life-threatening disease involving embolism and thrombosis of the small blood vessels in the brain and kidney.

Thrombus: An aggregation of fibrin and platelets within a blood vessel. A thrombus often causes vessel obstruction, inflammation, and injury.

Thrush: Fungal infection of the oral mucosa.

Thyroid-stimulating hormone (TSH): A polypeptide hormone secreted by the anterior pituitary gland that stimulates iodine uptake and thyroid hormone synthesis.

Thyrotropin-releasing hormone (TRH): A trophic hormone released by the hypothalamus that stimulates release of thyroid-stimulating hormone (TSH).

Time trade-off: An approach to health-state preference elicitation in which the respondent is asked to trade off years of life in less than full health for a shorter number of years in full health.

Tinea barbae: Fungal infection of the hair follicles of the beard or mustache.

Tinea capitis: Fungal infection of the scalp, hair follicles, or adjacent skin.

Tinea corporis: Fungal infection of the glabrous skin of the trunk and extremities.

Tinea cruris: Fungal infection of the proximal thighs and buttocks.

Tinea manuum: Fungal infection of the palmar surface of the hands.

Tinea pedis: Fungal infection of the feet.

Tinnitus: A noise in the ears, as ringing, buzzing, roaring, clicking, etc.

Tocolytic: Agent that stops labor contractions.

Tolerance: (1) A state of adaptation in which exposure to a drug induces changes that result in a diminution of one or more of the drug’s effects over time. (2) The ability of the immune system to accept a transplanted allograft as part of self.

Tonic-clonic seizures: Sharp tonic contraction of muscles followed by a period of rigidity and clonic movement.

Tophi: Urate deposits.

Total nutrient admixture: A parenteral nutrition formulation containing intravenous fat emulsion as well as the other components of parenteral nutrition (dextrose, amino acids, vitamins, minerals, water, and other additives) in a single container.

Toxic epidermal necrolysis: A syndrome similar to Stevens-Johnson syndrome characterized by blistering of skin and mucous membranes in response to administration of a drug. Large areas of skin may peel off.

Toxic megacolon: A segmental or total colonic distension of >6 cm with acute colitis and signs of systemic toxicity.

Toxic shock syndrome: Sudden onset of fever, muscle ache, vomiting and diarrhea, accompanied by a peeling rash and followed by low body temperature and shock; caused by staphylococcal endotoxin, especially from infection of the vagina associated with tampon use.

Toxoplasmosis: Clinical infection with Toxoplasma gondii.

Transmural: Across the wall of an organ or structure; in the case of CD, inflammation may extend through all four layers of the intestinal wall.

Transurethral incision of the prostate: In this surgical procedure, the bladder neck opening is widened by making incisions at various locations around the bladder neck with a resectoscope, which is inserted into the penis. Excess prostate tissue is not removed.

Transurethral prostatectomy: In this surgical procedure, an enlarged prostate core is removed from the inside out. That is, a resectoscope is inserted into the penis. A cutting blade at the end shaves out excess prostate tissue.

Transverse lie: The fetus is perpendicular to the mother. Usually the shoulder is the presenting part. Fetuses in this position must be delivered by cesarean section.

Transverse myelitis: Inflammation of the full width of the spinal cord that disrupts communication to the muscles, resulting in pain, weakness, and muscle paralysis.

Traveler’s diarrhea: Diarrhea caused by contaminated food or water and usually attributed to enterotoxigenic Escherichia coli (ETEC), ShigellaCampylobacterSalmonella species, or viruses.

Triple-negative breast cancer (TNBC): Breast cancer cells lacking estrogen, progesterone, and HER2 receptor protein overexpression.

Troponins T or I: Proteins found predominately in cardiac and not skeletal muscle that regulates calcium-mediated interaction of actin and myosin. Troponin I and T are released into the blood from the myocytes at the time of myocardial cell necrosis secondary to infarction. These biochemical markers become elevated and are used in the diagnosis of myocardial infarction. Troponin I and T are more sensitive and specific for infarction than creatine kinase, which is found in both skeletal and myocardial cells. The exact value of troponin I or T, which is diagnostic of infarction, differs based on assay.

Trousseau’s sign: A hand spasm produced by placing a blood pressure cuff over the forearm and inflating the pressure above the systolic pressure for 3 minutes.

Tubule: Section of the nephron that is responsible for secretion and reabsorption of water, electrolytes, and drugs.

Tumor: Elevated, solid lesion.

Tumor necrosis factor-α (TNF-α): A proinflammatory cytokine.

Type I reaction: An immediate, immunoglobulin E (IgE)-mediated allergic reaction.

Ulcer: Loss of epidermis and dermis caused by sloughing of necrotic tissue.

Ultradian sleep–wake rhythm: Is a cycle of sleep and wake that repeats in less than 24 hours. Babies have an ultradian sleep–wake rhythm with multiple sleep and wake periods in a 24-hour period.

Ultrafiltration: The process of removing water from the blood during dialysis.

Ultraviolet A light: 315–400 nm ultraviolet A light.

Ultraviolet A light 1: 340–400 nm ultraviolet A light.

Ultraviolet B light, broadband: 280–315 nm ultraviolet B light.

Ultraviolet B light, narrow band: 311 nm ultraviolet B light.

Umbilication: Slight, navel-like depression, or dimpling, of the center of a rounded body.

Unilateral: On either the right or left side, not crossing the midline. When used for defining sensory or motor disturbances of migraine aura, it includes complete or partial hemi-distribution; not just applicable to migraines, but to just about any disease related to anatomical structure(s).

Upper respiratory tract infection: Otitis media, sinusitis, pharyngitis, laryngitis (croup), rhinitis, or epiglottitis.

Urea: A waste product found in the blood and caused by the normal breakdown of protein in the body.

Uremia: An array of symptoms associated with accumulation of metabolic by-products and endogenous toxins in the blood due to impaired kidney function. Symptoms include nausea, vomiting, loss of appetite, weakness, and mental confusion.

Urethritis: Inflammation of the urethra.

Urinalysis: The diagnostic analysis of urine and its components; can be microscopic or macroscopic in nature.

Urinary incontinence: Involuntary leakage of urine; can result from urethral underactivity (stress urinary incontinence), urethral overactivity (overflow incontinence), or mixed pathophysiologic mechanisms.

Urine: Fluid waste resulting from filtration of blood by the kidneys; transferred to the bladder by ureters and expelled from the body through the urethra by the act of voiding or urinating.

Urticaria: Hives (red, raised bumps) that may occur after exposure to an allergen.

USP Chapter 797: A chapter of the United States Pharmacopeia (USP) that details the procedures and requirements for compounding sterile preparations and sets standards that are applicable to all practice settings in which sterile preparations are compounded.

Vacuum erection device: Medical device used to manually induce an erection.

Vagal nerve stimulator (VNS): A medical device that is surgically implanted in patients with refractory epilepsy.

Validity: An estimation of the extent to which an instrument is measuring what it is purported to be measuring.

Valsalva maneuver: The Valsalva maneuver is the expiratory effort against a closed glottis, which increases thoracic cavity pressure, which impedes venous return to the heart. This maneuver results in blood pressure and heart rate changes and is used to diagnose treat various cardiac conditions.

Vasculitis: Inflammation of blood vessels.

Vasopressin: A posterior pituitary hormone that controls fluid balance by acting on the renal collecting ducts to prevent water loss.

Vector: Carrier (person, animal, or insect) of disease.

Vegetation: Bacterial growth on heart valves.

Ventricular remodeling: Alterations in myocardial cells and the extracellular matrix that result in changes in the size, shape, structure, and function of the heart. The remodeling process leads to reductions in myocardial systolic and/or diastolic function that, in turn, leads to further myocardial injury, perpetuating the remodeling process and the decline in ventricular dysfunction and progression of heart failure.

Vesicle: Clear blister (<0.5 cm in diameter) filled with fluid.

Visceral pain: Pain arising from internal organs such as the large intestine or pancreas.

Visual analog scale: A response scale that is a line with the end points well defined (e.g., 0 = worst imaginable health state, and 100 = best imaginable health state).

Visuospatial: Denoting the ability to comprehend visual representations and spatial relationships in learning and performing a task.

Volume of distribution: A proportionality constant that relates the amount of drug in the body to its serum concentration.

Vomiting: Contraction of the abdominal muscles, descent of the diaphragm, and opening of the gastric cardia resulting in expulsion of stomach contents from the mouth.

Vulgaris: Ordinary, common.

Wearing-off phenomena: Also known as end-of-dose wearing-off or motor fluctuations. The waning of the effects of a dose of levodopa prior to the scheduled time for the next dose, resulting in return of parkinsonian features, such as, tremor, slowness, and rigidity.

Wernicke’s encephalopathy: A serious neurologic disorder caused by thiamine deficiency.

White coat hypertension: Patients have normal BP measurements based on home measurements but have elevated BP measurements when measured in a clinical setting.

Withdrawal: The development of a substance-specific syndrome after cessation of or reduction in intake of a substance that was used regularly by the individual to induce a state of intoxication. Withdrawal causes significant distress to the individual and is associated with impairment in social, occupational, or other areas of functioning. Withdrawal is usually associated with substance dependence. Withdrawal generally is also associated with a craving to readminister the drug to relieve the symptoms.

Withdrawal bleeding: The predictable bleeding that results from cessation of a progestogen.

Withdrawal syndrome: The onset of a predictable constellation of signs and symptoms involving the central nervous system after the abrupt discontinuation of, or rapid decrease in, dosage of a drug.

Xerosis: Dry skin.

Xerostomia: Dry mouth caused by decreased salivary production.

Yeasts: Oval or spherically shaped unicellular forms that generally produce pasty or mucoid colonies on agar media, similar to those observed with bacterial cultures. Yeasts have rigid cell walls that reproduce by budding, a process in which daughter cells arise from pinching off a portion of the parent cell.

Zeitgeber: Environmental cue.

Zollinger–Ellison syndrome: Gastric acid hypersecretory disease caused by a gastrin-secreting tumor and leading to multiple, severe duodenal ulcers.