The Mystery of Sleep: Why a Good Night's Rest Is Vital to a Better, Healthier Life


Medical Conditions That Affect Sleep


THE MYSTERY. Why do so many medical disorders, including hormonal abnormalities, diabetes, cardiovascular diseases, and arthritis, result in sleep disorders?

The Case of the Woman with a Black Curtain

The woman sitting in front of me was in her seventies, articulate, and obviously distressed. She had just walked perhaps ten yards from the waiting room to my office and she was breathless, almost panting. I let her settle down, and when she had composed herself, I started to interview her, expecting her to focus on sleep issues—after all, she was at a sleep clinic! Instead, she told me that a black curtain had descended over her mind, and because of it she could no longer continue her work as a visual artist. She was trying to prepare for an art show, but she was unable to work. Although she admitted to having trouble sleeping, she insisted that her main problem was that her creativity had been blocked by the black curtain.

Her family doctor, on the other hand, believed that her main problem was the insomnia and had referred her to the sleep clinic. I examined the woman and found that she had swollen ankles and noises in her lungs. This told me that an entirely different organ system was causing her insomnia, and I knew I would be able to help her lift the black curtain.

Chronic Medical Problems Can Lead to Sleep Problems

Insomnia is often a symptom of a disease. When a person is suffering from insomnia, he or she should consult a doctor, who needs to determine the cause of the symptom and then treat it. In addition to the triggers discussed in Chapter 10, insomnia can be caused by many different medical problems. A disturbance in sleep often indicates that there is something else wrong in the body, and the problem might be serious. Disorders involving almost every single organ system can cause problems with sleep. This is why it is imperative for doctors to ask their patients about how they are sleeping (though until recently they seldom did) and for patients to describe sleep problems when they see a doctor.

Name any chronic disease, and you will find that it is probably associated with a sleep problem. Diabetes, kidney failure, arthritis, Parkinson’s, heart failure, and cancer are some of the commonly occurring medical conditions that can affect sleep and lead to sleep complaints. And a host of psychiatric complaints—depression, bipolar disorder, obsessive-compulsive disorder—also have insomnia as an important symptom. (These will be reviewed in Chapter 16.) Diseases and disorders of the nervous, pulmonary, cardiovascular, and urinary systems and the gastrointestinal tract, imbalances and problems affecting the sinuses and hormones, and some other conditions can all cause sleep problems. A variety of sleep problems are also associated with cancer.

Diseases and Disorders of the Nervous System

The nervous system is made up of the brain, the spinal cord, and the nerves that go to all parts of the body, including to the organs, muscles, and skin. Because the system that controls sleep is in the brain, disorders of the nervous system are likely to result in disturbed sleep.


Alzheimer’s is a neurodegenerative disorder in which the nervous system deteriorates, usually owing to an accumulation of beta-amyloid, a chemical in the brain that forms plaques, and strands of a protein called tau, which appear to choke off normal brain cells and their ability to communicate with each other. Inflammation, perhaps as a response to infection, may play a role. The dis order can progress very rapidly or slowly, with a gradual loss of brain function (including the ability to sleep) over a period of many years. Lewy Body Dementia, a less common disease, shares some of the symptoms of Alzheimer’s. Cognitive decline and memory problems are the main symptoms.

The statistics concerning Alzheimer’s are staggering. In the United States, it was estimated in 2016 that there were 5 million people living with the disease and that by 2050 that number will be about 14 million people. It has been estimated that one in nine of all Americans over age sixty-five, and perhaps half of people older than eighty-five, have Alzheimer’s. Because women on average live longer than men, many more women have Alzheimer’s than men. It has also been suggested that within a given age group, a woman is more likely to have Alzheimer’s than a man. A study from Denmark estimated that of a hundred women age ninety or older, eighty had Alzheimer’s; in contrast, of a hundred men age ninety or older, twenty-four had Alzheimer’s. Besides the primary symptoms of the disease, 42 percent of Alzheimer’s patients are depressed.

Recent research suggests that sleep apnea may contribute to the cognitive decline of Alzheimer’s patients. Thus, treating their sleep apnea (see Chapter 12) might slow cognitive decline. This is an exciting development. People with severe Alzheimer’s may spend a great deal of time awake at night, and many may reverse their days and nights, sleeping fitfully throughout the day and remaining awake all night. In addition, some Alzheimer’s patients may experience sundowning, a condition that usually occurs in the late afternoon or early evening, in which the patient becomes agitated and has hallucinations or episodes of anxiety. It is believed that this symptom might be related to a breakdown of the circadian clock or be due to poor quality sleep. Sundowning is common among elderly people in general, not solely Alzheimer’s patients. About one in five institutionalized older people experiences sundowning.

New medications are available that seem to slow the pace of Alzheimer’s and might result in some improvement in brain function. These drugs can cause nausea, vomiting, diarrhea, and insomnia, however, and their effect on Alzheimer’s patients’ sleep patterns has not been widely studied. Sometimes patients are given other medications, such as antidepressants, that also might cause insomnia. Recent research suggests that exposure to light during the daytime could be helpful in improving nighttime sleep because it helps reset the patient’s circadian clock. Some scientists have recommended the use of melatonin, a hormone that is sometimes recommended for sleep problems (see Chapter 20). Several studies have suggested that melatonin at a dosage of 6 to 9 milligrams may be effective in improving sleep and treating sundowning in Alzheimer’s patients.


Headaches can be associated with sleep and other medical disorders. Some people with sleep-breathing problems awaken with headaches; it is common, for example, among people with sleep apnea. Not breathing enough causes an increase in the carbon dioxide level in the blood, and this leads to an increase in blood flow to the brain, putting extra pressure in the brain. Some patients have severe headaches that always begin during sleep. These can occur infrequently or almost every night. Little is known about these headaches, though some reports suggest that such headaches can be treated with caffeine, or lithium (a drug used to treat bipolar disease), flunarizine (a drug used to treat migraines), indomethacin (an anti-inflammatory), or Topamax (an anti-epilepsy medication). Some patients do not respond to any treatment.

Headaches are much more common in women than men. The only exception is the cluster headache, a less common type of headache, which is diagnosed more often in men. People with severe headaches often have difficulty falling and staying asleep. Two types of severe headaches that typically have an effect on sleep are migraines and cluster headaches.

Migraines. Migraine headaches, which are about three times more common among women than men, can be incapacitating. These headaches often affect only one side of the head and consist of a throbbing pain, sometimes accompanied by nausea and vomiting and/or increased sensitivity to light, sounds, and smells. For many people, migraine attacks are recurrent, though they tend to become less severe with aging. Many people begin to see shimmering lights around objects, zigzag lines, and wavy images about ten to thirty minutes before the onset of a migraine. Some experience hallucinations or even lose their vision temporarily. Not only do these headaches interfere with sleep, but also the ensuing sleep loss may cause the migraines to become more frequent. I recommend that people with severe migraine headaches (indeed, any severe headache) be evaluated and treated by a neurologist specializing in headaches.

Cluster headaches. The cluster headache is perhaps the most severe form of headache. The headache episodes occur in clusters or one after another within a short period of time, often lasting two to four months. During one of these clusters, the person might have two to ten headaches a day, often occurring at the same time each day like clockwork until the cluster ends. A period of several months or even years might follow before the next cluster begins.

The cluster headache is on one side of the head and face and often begins with a drooping of the eyelid, tearing, and enlargement of the pupil of the eye on the affected side. The pain becomes unbearable after five to ten minutes. The headache usually lasts about thirty to forty-five minutes (although some last up to two hours). Once the headache starts to subside, the pain might dissipate within five to ten minutes. The headaches are so severe that people pace, rock their bodies, and sometimes bang their heads against a wall to try to stop the pain. These headaches commonly start during sleep, particularly dreaming (REM) sleep, and frequently the pain awakens the sufferer. People with cluster headaches should seek medical help, though because some doctors consider this type of headache a male phenomenon—it is roughly twice as common in men—they often miss it in women. Women experiencing this disorder should describe their symptoms as precisely as possible. These headaches sometimes respond to breathing oxygen, as well as to some of the medications used to treat migraine headaches.


Parkinson’s disease is a common neurological problem that affects the parts of the brain that produce the chemical dopamine. Parkinson’s affects about 1 million Americans and 10 million people worldwide. The disease causes involuntary movements including tremors, masklike facial expressions, and an abnormal gait. Parkinson’s disease occurs more frequently in older people, and is 50 percent more common in men than women.

About 60 percent of people with Parkinson’s disease have trouble falling and staying asleep. Experiencing restless legs syndrome (see Chapter 11) and repetitive twitches in their legs as they sleep is common among these patients. They might awaken during the night and be unable to fall asleep again. Sometimes this is the result of their medication wearing off and being eliminated from the body. Sometimes days and nights become reversed.

About a third of patients have REM behavior disorder, a condition in which the sleeper physically reacts to the content of his or her dreams (see Chapter 14). Patients with this condition can harm themselves or their bed partners. Many patients also experience frightening hallucinations while they are awake. As a result of RBD, sleep apnea, a movement disorder, or the medications used to combat the disease, patients can experience severe daytime sleepiness. Some doctors have begun to treat this severe daytime sleepiness with the wakefulness-promoting medication modafinil. When taken in the morning, modafinil does not interfere with a patient’s ability to sleep at night (see Chapter 20).

Diseases and Disorders of the Pulmonary System

Any lung problem, most commonly asthma and chronic obstructive pulmonary disease (COPD) that causes excessive coughing, wheezing, or shortness of breath at night, can lead to insomnia.


Asthma, which is the constriction of the bronchial tubes causing excessive coughing and shortness of breath, affects roughly 8 percent of the U.S. population. Until they reach thirty years of age, men are more likely to have asthma than women. After age thirty, it is about twice as common among women than men. This is important because when the disease starts at a younger age it tends to improve, while in the older age groups in which women predominate, it is much less likely to improve. Female asthmatics have a 70 percent higher risk of being admitted to the hospital for asthma than their male counterparts.

Medication usually relieves the symptoms of asthma. For some people, however, the first sign that their asthma is not under control is when they develop a wheeze that awakens them from sleep. Sometimes a sleeper who is awakened by coughing does not understand what is happening. Some patients who are referred to me because of insomnia discover the extent to which the coughing disturbed their sleep only after they have had a sleep test.


Chronic obstructive pulmonary disease (emphysema) occurs in long-time cigarette smokers. It is most often irreversible and can be fatal. Research suggests that tobacco has a greater adverse effect on lung function in women than men, and women are more likely to be hospitalized for COPD. As with asthma, coughing and shortness of breath are common symptoms of COPD. In addition, because many COPD sufferers continue to be cigarette smokers, they often wake up during the night craving nicotine. Some people awaken in the morning with their lungs filled with sputum, which they have to cough up in order to breathe normally. The combination of waking up with coughing and shortness of breath makes it difficult for these patients to have restful sleep.

Diseases and Disorders of the Cardiovascular System

Although there is a widespread belief that diseases of the heart and blood vessels affect mainly males, this is not true. In fact, about sixty thousand more women than men die each year of cardiovascular disease in the United States. In 2015, about 80 million Americans were estimated to have cardiovascular diseases. Recent research has shown that cardiovascular diseases can cause sleep problems—and sleep disorders can cause cardiovascular diseases.


Angina occurs when the muscles of the heart suddenly, but temporarily, stop receiving enough blood flow, but the muscle is not damaged. The main symptom is chest pain brought on by exertion, which is relieved within minutes of stopping the exertion (such as exercise) or a medication that dilates the coronary arteries. Patients with coronary artery disease may develop symptoms of angina when they sleep, if they have sleep apnea, or sometimes during dreaming sleep, when the arteries to the heart may go into spasm. Patients with this symptom should report it to their doctor.


A heart attack (what doctors call a myocardial infarction) occurs when the muscles of the heart are suddenly deprived of blood flow, and the muscle is damaged. Diseases of the blood vessels of the heart (the coronary arteries) are the most common cause. Women who are having a heart attack can have different symptoms from men. Although chest pain is considered the classic symptom of a heart attack, research reported in the United States in late 2003 found that 43 percent of women did not have chest pain during a heart attack. However, 70 percent of women who had a heart attack suffered from fatigue and about half had had trouble sleeping in the weeks before the episode. Fatigue was the most common symptom.


Heart failure (often called congestive heart failure, CHF) occurs when a weakened heart muscle cannot pump enough blood to meet the body’s requirements for blood and oxygen. There are many causes; the most common is having had a heart attack that has permanently damaged the heart. About 6 million Americans suffer from some form of heart failure. Although this has commonly been considered a problem affecting men, statistics indicate that heart failure is a bigger problem for women. In 2016, about 3 million women in the United States were living with heart failure compared to 2.7 million men. More women than men die of heart failure.

Some people with heart failure develop a sleep-breathing pattern that at times becomes progressively deeper, then progressively shallower. Sometimes breathing stops completely for short periods of time. To restart the breathing the brain has to go through a mini-awakening. When the pattern of breathing too much followed by breathing too little repeats itself about once a minute it is a sign of sleep apnea, which results in insomnia. People with heart failure frequently have trouble falling asleep, and when they awaken during the night they are frequently extremely short of breath and feel as though they must sit up. Some of the medications used to treat heart failure, such as water pills and diuretics, may result in frequent trips to the bathroom at night, which also disrupt sleep.

People with heart failure might face the unfortunate combination of extreme sleepiness (because their sleep is so disrupted) and an inability to fall asleep. Research is still ongoing to evaluate oxygen and breathing devices that normalize the breathing pattern in these patients.


Some people awaken during the night with an abnormal heart rhythm. They might notice that the rhythm seems very fast or very slow, or they might feel an irregularity, such as an extra or missed beat. They might notice that they have to urinate at night. Some people are woken up by frightening dreams; in these cases, the palpitations might not be a medical problem. In other cases, however, the symptom could represent a significant cardiac arrhythmia that should be evaluated by a doctor.

Some people awaken from sleep with a rapid heartbeat, sweating, and the feeling that they are about to die. Sometimes this feeling of impending doom is caused by a panic disorder, which for some occurs mostly at night; it can also be a symptom of posttraumatic stress disorder (see Chapter 16). The episodes can be so alarming that the sufferer could develop a fear of falling asleep.


The heart pumps blood in arteries to the rest of the body. The amount and speed of blood the heart pumps and the resistance to blood flow in the arteries determine the pressure inside the arteries. This resistance could be increased by diseases such as atherosclerosis. In order for blood to pass through restricted arteries the pressure in the arteries is increased. Long-term increase in blood pressure is called hypertension, a major cause of heart disease, stroke, and kidney disease, which are all associated with sleep issues. When blood pressure is measured, two numbers are recorded: systolic blood pressure (the normal is up to 120) is the pressure while the heart is pumping; diastolic pressure (the normal is up to 80) is the pressure while the heart is relaxing. Thus a normal blood pressure would be 120/80. Hypertension is defined when either the systolic pressure is greater than 140 or the diastolic pressure is greater than 90. Hypertension is very common, and increases with age. In 2016 it was estimated that about a third of Americans aged forty-five to fifty-five and about two-thirds aged sixty-five to seventy-four have hypertension. Hypertension is generally treated with medications and lifestyle modifications such as diet and exercise.

Scientists have now shown that sleep apnea can cause high blood pressure; it can also make control of blood pressure with medications more difficult. Some medications used to treat high blood pressure, such as beta blockers, may cause insomnia and nightmares.

Diseases and Disorders of the Urinary System

The urinary system is made up of two parts. The kidneys maintain fluid balance in the body, keep electrolytes (such as sodium and potassium) at safe levels, and remove toxins while producing urine. The second part consists of tubes that carry the urine from the kidneys to the bladder, which stores the urine. When the bladder is full and the person urinates, the fluid goes from the bladder via another tube called the urethra before leaving the body. In males, in front of the urethra near the bladder is the prostate gland. Quite a journey!

When a person reduces his or her fluid intake, the kidneys try to keep water in the body, and urine becomes concentrated, but for sufferers from certain kidney diseases (diabetes, failing kidneys), the urine does not become concentrated. The urinary systems of these people consequently produce too much urine and they have to go to the bathroom many times a night, disrupting sleep. If kidney function fails and the patient has to go on dialysis, he or she frequently will experience very severe movements or restless legs syndrome, which inhibits sleep. Menopausal women and older men (especially if their prostates are enlarged) need to go to the bathroom more often at night and may have a great deal of difficulty falling asleep again. People with untreated sleep apnea frequently have to urinate at night.

Diseases and Disorders of the Gastrointestinal Tract

There are several common diseases of the gastrointestinal tract that disturb sleep.


At the bottom of the esophagus (the tube that carries food from the mouth into the stomach) is a sphincter that keeps stomach acid from entering the esophagus. Sometimes this sphincter does not work properly, and acid backs up into the esophagus (a process known as reflux) and causes heartburn. In the most severe situation, called gastroesophageal reflux disease (GERD), the acid can damage the esophagus. Gastroesophageal reflux is a common condition that affects men and women equally; scientists estimate that perhaps 30 to 40 percent of the adult population in the United States suffers from a reflux disorder. Women who are overweight or pregnant women have a higher risk for reflux.

When GER occurs at night, it can keep the sufferer from falling or staying asleep. Gastroesophageal reflux can affect sleepers in a variety of ways. The acid might make its way all the way up to the mouth and awaken the sleeper with a bitter taste or with severe coughing and choking. If the acid touches the vocal cords, they can sometimes go into spasm, and the person will feel unable to breathe and as though he or she were going to die. Additionally, GER can cause heartburn, which often awakens the sleeper. Research has shown that even when the acid enters the esophagus without causing pain, it might still awaken the sleeper.

Twenty years ago, there were few effective medications for gastroesophageal reflux. Today doctors can prescribe excellent medications that shut down the stomach’s production of acid. These drugs fall into two main categories: blockers of a type of histamine receptor—for example, famotidine, ranitidine, cimetidine, which are now available over the counter—and a class of drugs called proton-pump inhibitors that includes rabeprazole (AcipHex), esomeprazole (Nexium), lansoprazole (Prevacid), and omeprazole (Prilosec).


When the stomach produces too much acid or cannot properly deal with the normal acids it produces, an ulcer can form in the stomach or in a tube called the duodenum. Often the disease is caused by an infection from a bacterium called Helicobacter pylori. Some medications, such as certain nonsteroidal anti-inflammatory drugs, even when used as prescribed, can cause ulcers. People with peptic ulcer disease frequently awaken one or two hours after going to sleep with either pain or the sensation of hunger. Eating food or taking ant-acids often relieves the pain temporarily. Peptic ulcer disease can cause serious complications, such as bleeding in the intestinal tract. People experiencing severe pain that wakes them from sleep should seek medical help. Excellent treatments, such as antibiotics and proton-pump inhibitors, are available for peptic ulcer disease, and these can also help the sufferer regain a normal sleep pattern.

Sinus Disease

Over the years, I have seen many people who start coughing after they lie down. Frequently they might have a cold or a sinus infection before the cough begins, but they do not cough during the day. As soon as they lie down, however, they get coughing fits. It is likely that the lying down causes their sinuses to drain and some of the secretions may make contact with the vocal cords, leading to the coughing. For some people, this problem might go on for months, and sufferers might be treated for a lung disease such as asthma before the true culprit—draining sinuses—is discovered. In the meantime, their coughing causes them to lie awake or wake up during the night, which affects the quantity and the quality of their sleep.

Diseases and Disorders of Hormone Production


Most diseases involving hormone production can cause disturbed sleep. Some of these diseases are common, and some are much more common among women than men. One of the most frequently found is diabetes.

When a person has diabetes, either the body doesn’t produce enough of the hormone insulin or there is a resistance to insulin’s effect on cells of the body, resulting in high blood sugar levels. In 2012, 9.3 percent of the U.S. population, 29.1 million people, had diabetes. The prevalence of diabetes varied according to ethnic and racial group: diabetes was present in 7.6 percent of non-Hispanic whites, 9 percent of Asian Americans, 12.8 percent of Hispanics, 13.2 percent of African Americans, and 15.9 percent of American Indians/Alaskan Natives. Research has shown that about 50 percent of people with diabetes experience sleep problems. There are many reasons why they develop these difficulties. First, when blood sugar is too high, the kidney filters the sugar into the urine, which forms more urine than normal and results in an increased need to go to the bathroom, disrupting sleep.

In addition, diabetics might develop blood sugar levels during the night that are too low, which will cause them to awaken with sweating, hunger, and a rapid heart rate. This symptom usually occurs when they have taken too much insulin or have eaten too little food before bedtime.

Patients with the most severe forms of diabetes develop nerve damage called neuropathy. This may cause excessive movements or unpleasant sensations in the legs, such as restless legs syndrome, or pain, all of which keep the sufferers from falling asleep. In addition, the neuropathy might affect the nerves of the gastrointestinal tract, and some patients with diabetes suffer from diarrhea at night, which also affects their sleep adversely.


The thyroid gland is located in the neck in front of the trachea (the breathing passage) right below the Adam’s apple. This crucial and sensitive gland produces thyroid hormone, which is involved in the regulation of metabolism in most of the body’s cells. All thyroid disorders are five times more common among women than men.

Goiter. In some people, the thyroid gland enlarges to such an extent that it starts to block the breathing passage behind it. Most of the time, this is due to enlargement of the cells, sometimes caused by a deficiency of iodine. This condition is called a goiter. When the gland becomes too large, and the breathing passage is significantly blocked, the person might develop sleep apnea. Surgery is often used to remove such an enlarged thyroid.

Hypothyroidism. Sometimes the thyroid gland does not produce enough hormone. This condition, called hypothyroidism, may come on over a period of months, even years. The skin becomes coarse and dry and the hair might start to fall out. The sufferer will gain weight, sometimes becoming clinically obese (BMI of more than 30). The weight gain is caused by a drop in the metabolic rate due to lack of thyroid hormone. With this condition, the person will eat the same amount of food as usual, but because fewer calories are burned, his or her weight increases. Hypothyroidism is at least twice as common among women as men.

Important symptoms of thyroid deficiency include feelings of fatigue (muscle weakness) and sleepiness, which can be debilitating. When the disease is severe, patients might actually lose consciousness and develop a breathing problem that requires immediate treatment. One of the reasons patients who are deficient in thyroid hormone suffer from sleepiness might be sleep apnea. This form of apnea usually develops because the thyroid patient’s tongue becomes so enlarged that it blocks the breathing passage during sleep.

The ideal treatment for these patients is thyroid replacement medication: a hormone that replaces the hormone their bodies fail to produce. This hormone replacement medication is usually very effective. Most people with hypothyroidism are prescribed a low dose of hormone to start because their metabolic rate is so low that a normal dose of thyroid might bring on symptoms of hyperthyroidism (see below). Often the dosage is slowly increased over a matter of weeks or months. It is vital that the patient see a doctor regularly to monitor the dosage. I have seen many patients at the sleep clinic who have low or deficient thyroid levels because they have not had their doses increased. Without the correct dosage they continued to have symptoms of low thyroid levels.

Hyperthyroidism. Hyperthyroidism is another major malfunction of the thyroid gland. Like the other thyroid conditions, it is far more common (five to ten times) among women than men. In this disorder, too much hormone is produced and the person becomes hypermetabolic—burning up more calories than he or she takes in. People with hyperthyroidism sweat, tremble, and lose a great deal of weight in a short period of time. Sometimes the disease will cause their eyeballs to bulge outward, a condition known as Graves’ disease. Patients with excessive thyroid hormone may find it very hard to fall or stay asleep. They frequently sweat at night and have nightmares that wake them. These patients are sleepy during the daytime and they become physically exhausted because the excess thyroid hormone can reduce muscle strength. Furthermore, hyperthyroidism can trigger an extremely rapid heart rate, which can cause symptoms such as dizziness and fainting. The rapid heart rate can also awaken the person during sleep. Hyperthyroidism is a serious medical condition that should be treated and monitored by a medical professional.


The pituitary gland is a pea-sized gland in the brain. This gland produces certain hormones and regulates others that are produced in glands in other parts of the body. There are two abnormalities of the pituitary gland that can affect sleep, acromegaly and tumors.

Acromegaly. In acromegaly the pituitary gland produces too much growth hormone. The effect of the overproduction varies depending on whether the patient has already stopped growing. A child with this condition might become extremely tall; the condition is called gigantism. People with this condition have a characteristic look. Besides being extremely tall, they have larger than normal jaws and foreheads owing to the excess growth hormone. When a person who has stopped growing begins to produce excess growth hormone, some parts of the body might begin to grow again—for example, the jaw and other parts of the face and even the hands and feet. If the disease is not controlled, it can have devastating effects on the body. The heart can become too large and fail. Severe arthritis might follow. Sleep problems can develop. Acromegaly patients have enlarged tongues, which can obstruct their breathing passage when they sleep, leading to severe sleep apnea.

I once had a patient who had been successfully treated for acromegaly with surgical removal of the part of her pituitary gland producing the growth hormone. She had been excessively sleepy for years before her doctor realized that the acromegaly had caused sleep apnea, which now needed treatment. This disorder can also lead to diabetes and might also cause other hormonal problems, especially if the cause of the excess hormone production is a tumor.

Tumors. When tumors of the pituitary become too large, they can squeeze the normal parts of the gland and compress another important area of the brain called the hypothalamus. When this happens, the system responsible for regulating sleep and wakefulness might not work properly, and the person could experience severe sleepiness or develop a random sleep pattern, falling asleep at inappropriate times. But while the tumor is still growing, it is often difficult to diagnose the problem. If it becomes large enough to compress some of the nerves involved in vision it might impair the patient’s peripheral vision, causing him or her to bump into things. Doctors can be alert to this symptom. Pituitary tumors can also compress the normal tissue in this gland, which can in turn reduce the secretion of other hormones, including the sex hormones. Another sign that doctors look for in diagnosing and treating pituitary diseases is a reduction in the amount of hair in the pubic area and the armpits. A tumor growing in the pituitary can affect sleep directly, or cause other medical problems that affect sleep.

Arthritis, Fibromyalgia, and Chronic Fatigue Syndrome

These conditions share several features, such as pain, disturbed sleep, and nonrestorative sleep. When patients awaken they may feel as though they have not slept at all or not slept enough.

Arthritis. Many types of arthritis are caused by painful chronic inflammation (or destruction) of the joints. Some affect the larger joints (for example, the hips and the knees), while others affect smaller joints of the hands and feet. These conditions can lead to serious insomnia. Diseases of joints such as rheumatoid arthritis are about three times more common in women than men.

Fibromyalgia. Women in particular are often affected by a condition called fibromyalgia, which is also associated with excessive sensitivity to and perception of pain in the muscles and elsewhere. (This condition is about nine times more common among women than men.) People with fibromyalgia report that the pain is greater following a poor night of sleep. Any painful sensation can lead to trouble sleeping, daytime sleepiness, fatigue, or tiredness. Treatments include pain medicines (but not opiates), antidepressants, and muscle relaxants. The following medications have been approved by the U.S. Food and Drug Administration specifically for fibromyalgia: pregabalin (Lyrica), duloxetine hydrochloride (Cymbalta), and milnacipran HCl (Savella). Some patients might not respond to treatment.

Chronic fatigue syndrome. People with chronic fatigue syndrome (CFS) have as their major complaint overwhelming fatigue (not sleepiness) that does not improve with rest. The disorder has also been called myalgic encephalomyelitis (focusing on the muscle and brain component) and systemic exertion intolerance disease. Patients with CFS cannot tolerate physical exertion; they become severely fatigued for long periods (often more than twenty-four hours) after any exertion. In addition to problems with memory and concentration, these patients share several symptoms with those who suffer from fibromyalgia: pain, insomnia, and nonrestorative sleep. Medical science has not yet determined the cause of this syndrome or found a specific treatment. Although it might seem counterintuitive, a 2016 report found that an exercise program might help the sleep and fatigue symptoms of these patients.


Sometimes an undiagnosed cancer might present with sleep symptoms. Recall the patient described in Chapter 6 with restless legs syndrome who was found to have a low level of ferritin, a marker of low iron levels in the body. It turned out that he had a slow-bleeding cancer in his gastrointestinal tract, and his sleep symptoms preceded the diagnosis of his cancer. Night sweats have been seen in some patients with cancer—for example, those with lymphoma.

People with a diagnosed cancer might experience sleep problems for a variety of reasons. The diagnosis itself causes stress, which can lead to insomnia. Additionally, cancer of a particular organ can cause sleep problems related to that organ. For example, a person with lung cancer might awaken with shortness of breath, or a person with cancer affecting the bones may have trouble sleeping because of pain. Finally, some of the treatments for cancer, such as chemotherapy, can result in severe symptoms such as nausea and vomiting, which can also affect sleep.

One 2002 study in the United States reported that the most common problems among cancer patients were fatigue (44 percent of patients), restlessness in the legs (41 percent), insomnia (31 percent), and excessive daytime sleepiness (28 percent). Sleep problems were most prevalent in patients with lung cancer. (A side note: since 1987, more women in the United States have died of lung cancer than of breast cancer.) Insomnia and fatigue were more common among patients with breast cancer.

Some treatments for breast cancer or ovarian cancer can lead to the immediate onset of menopause; we saw in Chapter 5 that this can interfere with sleep. Tamoxifen, for example, a widely used anti-estrogen drug for the treatment of breast cancer, can cause menopausal symptoms, including hot flashes and night sweats that might lead to insomnia. Some cancer patients who have been treated with chemotherapy or radiotherapy might experience severe daytime sleepiness or overwhelming tiredness. Some patients even develop neuropathy (nerve damage) and other symptoms suggesting restless legs syndrome due to chemotherapy drugs.

Many doctors do not ask their cancer patients about sleep problems. In cases in which the cancer is not cured, treatments are available for relief of the pain; help is also possible for patients who have trouble sleeping. For instance, restless legs syndrome can usually be successfully treated. A study reported in 2016 found that cognitive behavioral therapy (discussed in Chapter 19) can improve sleep in breast cancer survivors. If the sleep problem cannot be solved, the patient might want to try a sleeping pill or a wakefulness-promoting medication such as modafinil or armodafinil to allow him or her to stay alert during the day.

Pain and Pain Treatment

Pain from any condition can lead to insomnia. Patients with joint disease might find their sleep disturbed indefinitely unless they find relief from the pain, through either medication or joint replacement surgery. Research has shown that people with painful joint diseases or disc problems of the lower back can develop restless legs syndrome. Sleep is one of the first functions that suffers when people injure their back or sustain other injuries that cause ongoing discomfort. The first line of defense is to treat the problem causing the pain. If that does not work, the patient might need pain relief via medication or massage. If even these are ineffectual, the patient should be referred to a pain clinic. Such clinics are available in many large medical centers.

In several U.S. states doctors can prescribe cannabis to treat pain. (Some states have even approved the decriminalization of marijuana used for recreational use.) Several research studies have shown that cannabis can alleviate pain and improve sleep for some people. But it has also been reported that chronic cannabis users may experience very disturbed sleep when trying to stop.

Traumatic Brain Injury

People who have had a traumatic brain injury can be left with severe daytime sleepiness or insomnia. Such an injury can occur as a result of military activities, motor vehicle accidents, or sports injuries. Right after the injury, most patients spend more time in bed and sleep more. This might be related to damage to the brain centers that control sleep and wakefulness. The sleepiness might continue long-term. This symptom has been shown to improve with armodafinil, a medication used to treat the sleepiness of narcolepsy.

Back to the Woman with a Black Curtain

An overnight sleep test of the patient who complained of a black curtain that blocked her creativity confirmed that her breathing pattern was consistent with heart failure. In the sleep lab, she was tested while breathing oxygen supplied by small tubes ending near her nostrils. This improved her breathing and she slept more deeply. She was sent home on oxygen.

Once her breathing improved, her “black curtain” lifted. She was able to muster enough creative energy to put her art show together. But although her sleep was markedly improved, she still had an abnormal heart, which could not be treated further. Doctors can learn an important lesson from this case: Insomnia has many forms, many symptoms, and many causes. It can alert doctors to serious medical conditions, and by so doing save patients’ lives. In some cases, the last thing a person with insomnia needs is a sleeping pill. In every case, the first thing she or he needs is a diagnosis.

Many medical problems cause sleep difficulties, and sometimes diagnosing the sleep difficulty can uncover a medical condition. Because some medical problems are generally associated with men, doctors are more slow to diagnose them in women (and vice versa). It is never a good idea to ignore a sleep problem.