THE MERCK MANUAL HOME HEALTH HANDBOOK
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Insomnia and Excessive Daytime Sleepiness

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The most commonly reported sleep-related problems are insomnia and excessive daytime sleepiness (EDS).

  • Insomnia is difficulty falling asleep or staying asleep or a disturbance in sleep quality that makes sleep seem inadequate or unrefreshing.
  • EDS refers to being unusually sleepy or falling asleep during the day in people who are not sleep-deprived.

Difficulty falling and staying asleep and waking up earlier than desired are common among young and old. About 10% of adults have long-standing (chronic) insomnia, and about 50% sometimes have insomnia.

People with insomnia or EDS are sleepy, tired, and irritable during the day and have trouble concentrating and functioning. People with EDS may fall asleep when working or driving.

There are several types of insomnia:

  • Difficulty falling asleep (sleep onset insomnia): Commonly, people have difficulty falling asleep when they cannot let their mind relax and they continue to think and worry. Sometimes the body is not ready for sleep at what is considered a usual time for sleep. That is, the body's internal clock is out of sync with the earth's cycle of light and dark—a type of circadian rhythm sleep disorder. This problem is common among adolescents and young adults.
  • Difficulty staying asleep (sleep maintenance insomnia): Older people are more likely to have difficulty staying asleep than are younger people. People with this type of insomnia fall asleep normally but wake up several hours later and cannot fall asleep again easily. Sometimes they drift in and out of a restless, unsatisfactory sleep.
  • Early morning awakening: This type may be a sign of depression in people of any age.

Insomnia and EDS may be caused by conditions inside or outside the body. Some conditions cause insomnia and EDS, and some cause one or the other. Some people have chronic insomnia that has little or no apparent relationship to any particular cause.

Common causes: Insomnia is most often caused by

  • Poor sleep habits, such as drinking a caffeinated beverage in the afternoon or evening, exercising late at night, or having an irregular sleep-wake schedule
  • Mental health disorders, particularly mood and anxiety disorders
  • Other disorders such as heart and lung disorders, disorders that affect muscles or bones, or chronic pain
  • Stress, such as that due to hospitalization or loss of a job (called adjustment insomnia)
  • Excessive worrying about sleeplessness and another day of fatigue (called psychophysiologic insomnia)

Sleeping late or napping to make up for lost sleep may make sleeping during the night even harder.

EDS is most often caused by

  • Insufficient sleep despite having ample opportunity to sleep (called insufficient sleep syndrome)
  • Obstructive sleep apnea (a serious disorder in which breathing frequently stops during sleep—see Sleep Apnea)
  • Various disorders, particularly mental health disorders, brain or nerve (neurologic) disorders (such as encephalitis, meningitis, or a brain tumor), and disorders that affect muscles or bones
  • Disorders that disrupt people's internal sleep-wake schedule (circadian rhythm disorders), such as jet lag and shift work disorder

Most major mental health disorders are accompanied by insomnia and EDS. About 80% of people with major depression have EDS and insomnia, and about 40% of people with insomnia have a mental health disorder, usually a mood disorder.

Any disorder than causes pain or discomfort, particularly if worsened by movement, can cause brief awakenings and interfere with sleep.

Less common causes: Drugs, when used for a long time or when stopped (withdrawal), can cause insomnia and EDS.

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Many mind-altering (psychoactive) drugs can cause abnormal movements during sleep and may disturb sleep. Sedatives that are commonly prescribed to treat insomnia can cause irritability and apathy and reduce mental alertness. Also, if a sedative is taken for more than a few days, stopping the sedative can make the original sleep problem suddenly worse.

Sometimes the cause is a sleep disorder.

Central sleep apnea is often first identified when people report insomnia or disturbed or unrefreshing sleep. This disorder causes breathing to become shallow or to stop repeatedly throughout the night.

Narcolepsy (see Sleep Disorders: Narcolepsy) is a sleep disorder characterized by EDS with uncontrollable episodes of falling asleep during normal waking hours and sudden, temporary episodes of muscle weakness.

Periodic limb movement disorder (see Sleep Disorders: Periodic Limb Movement Disorder and Restless Legs Syndrome) interrupts sleep because it causes repeated twitching or kicking the legs during sleep. As a result, people are sleepy during the day.

Restless legs syndrome (see Sleep Disorders: Periodic Limb Movement Disorder and Restless Legs Syndrome) makes falling and staying asleep difficult because people feel as if they have to move the legs and, less often, the arms when they sit still or lie down. People usually also have creepy, crawly sensations in the limbs.

Usually, the cause can be identified based on the person's description of the current problem and results of a physical examination. Many people have obvious problems, such as poor sleep habits, stress, or coping with shift work.

Warning signs: Certain symptoms are cause for concern:

  • Falling asleep while driving or during other potentially dangerous situations
  • Frequently falling asleep without warning
  • Stopping breathing during sleep or waking up with gasping or choking (reported by a bed partner)
  • Moving violently or injuring self or others during sleep
  • Sleepwalking
  • A heart or lung disorder that is constantly changing (is unstable)

When to see a doctor: People should see a doctor if they have warning signs or if their sleep-related symptoms interfere with their daily activities. If healthy people have sleep-related symptoms for a short time (less than 1 or 2 weeks) but do not have warning signs, they can try changes in behavior that can help improve sleep (see Sleep Disorders: Changes in Behavior to Improve SleepTables). If these changes do not help after a week or so, people should see a doctor.

What the doctor does: The doctor asks people about their sleep patterns, habits around bedtime, use of drugs (including illegal drugs), use of other substances (such as alcohol, caffeine, and tobacco), degree of stress, medical history, and level of physical activity. People may be asked to keep a sleep log. In it, they record a detailed description of their sleep habits, with sleep and wake times (including awakening during the night), use of naps, and any problems with sleeping. When considering the diagnosis of insomnia, the doctor considers that some people need less sleep than others.

If people have EDS, the doctor may ask them to fill out a questionnaire indicating how likely they are to fall asleep in various situations. The doctor may ask their sleep partner to describe any abnormalities that occur during sleep, such as snoring and pauses in breathing.

A physical examination is done to check for disorders that can cause insomnia or EDS.

Testing: Doctors sometimes refer people to a sleep disorders specialist for evaluation in a sleep laboratory. Reasons for such a referral include

  • An uncertain diagnosis
  • Suspicion of certain disorders (such as sleep apnea, a seizure disorder, narcolepsy, and periodic limb movement disorder)
  • Insomnia or EDS persisting despite basic measures to correct it (changing behavior to improve sleep and taking sleep aids for a short time)
  • Presence of warning signs or other symptoms such as nightmares and twitching of the legs or arms during sleep
  • Dependence on sleep aids
  • An irresistible urge to move the legs or arms just before or during sleep

Tests are not needed if symptoms suggest a cause such as restless legs syndrome, poor sleep habits, stress, or shift work disorder.

The evaluation consists of polysomnography and observation (and sometimes video recording) of unusual movements during an entire night's sleep. Other tests are sometimes also done.

Polysomnography is usually done overnight in a sleep laboratory. Electrodes are pasted to the scalp and face to record the brain's electrical activity (electroencephalography, or EEG—see Symptoms and Diagnosis of Brain, Spinal Cord, and Nerve Disorders: Electroencephalography) as well as eye movements. These recordings help provide doctors with information about sleep stages. Electrodes are also attached to other areas of the body to record heart rate (electrocardiography, or ECG), muscle activity (electromyography), and breathing. A painless clip is attached to a finger or an ear to record oxygen levels in the blood. Polysomnography can detect breathing disorders (such as obstructive sleep apnea), seizure disorders, narcolepsy, periodic limb movement disorder, and unusual movements and behaviors during sleep (parasomnias).

A multiple sleep latency test is done to distinguish between physical fatigue and EDS and to check for narcolepsy. People spend the day in a sleep laboratory, taking four or five naps at 2-hour intervals. Polysomnography is used as part of this test to assess how quickly people fall asleep. It detects when people fall asleep and is used to monitor the stages of sleep during the naps.

The maintenance of wakefulness test is used to determine how well people can remain awake while sitting in a quiet room.

Tests to evaluate the heart, lungs, and liver may be done in people with EDS if symptoms or results from the physical examination suggest that another disorder is the cause.

Treatment of insomnia depends on its cause and severity. If insomnia results from another disorder, that disorder is treated. Such treatment may improve sleep.

If insomnia is mild, general measures may be all that is needed. They include

  • Changes in behavior (such as following a regular sleep schedule and avoiding caffeine after lunch time)
  • Prescription sleep aids
  • Nonprescription sleep aids

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If stress is the cause, reducing stress, if possible, typically eliminates the symptoms. If symptoms persist, talk therapy (cognitive-behavioral therapy), done by trained specialists, may be the most effective and safest treatment. It helps people understand the problem, unlearn bad sleeping habits, and eliminate unhelpful thoughts, such as worry about losing sleep or the next day's activities. This therapy also includes relaxation training. But if daytime sleepiness and fatigue develop, especially if they interfere with daytime functioning, treatment with sleep aids is warranted for a short time. A combination of cognitive-behavioral therapy and sleep aids is often best.

If people have insomnia and depression, the depression should be treated, often relieving the insomnia. Some antidepressant drugs also have sedative effects that help with sleep when the drugs are given before bed. However, these drugs may also cause daytime sleepiness, particularly in older people.

Prescription sleep aids: When a sleep disorder interferes with normal activities and a sense of well-being, taking prescription sleep aids (also called hypnotics or sleeping pills) occasionally for up to a few weeks may help.

Prescription Sleep Aids: Not to Be Taken Lightly

Among the most commonly used sleep aids are sedatives, minor tranquilizers, and antianxiety drugs (see Drug Use and Abuse: Antianxiety and Sedative Drugs). Most are safe as long as a doctor supervises their use.

Most sleep aids require a doctor's prescription because they may cause problems. Many of these problems are less common with newer sleep aids.

  • Loss of effectiveness: Once people become accustomed to a sleep aid, it may become ineffective. This effect is called tolerance.
  • Withdrawal symptoms: If a sleep aid is taken for more than a few days, stopping it can make the original sleep problem suddenly worse (causing rebound insomnia) and can increase anxiety. Thus, doctors recommend reducing the dose slowly over a period of several weeks until the drug is stopped.
  • Habit-forming or addiction potential: If people use sleep aids for more than a few days, they may feel that they cannot sleep without them. Stopping the drug makes them anxious, nervous, and irritable or causes disturbing dreams.
  • Potential for overdose: If taken in higher than recommended doses, some of the older sleep aids can cause confusion, delirium, dangerously slow breathing, a weak pulse, blue fingernails and lips, and even death.
  • Serious side effects: Most sleep aids, even when taken at recommended doses, are particularly risky for older people and for people with breathing problems because sleep aids tend to suppress areas of the brain that control breathing. Some can reduce daytime alertness, making driving or operating machinery hazardous. Sleep aids are especially dangerous when taken with other drugs that can cause daytime drowsiness and suppress breathing, such as alcohol, opioids (narcotics), antihistamines, or antidepressants. The combined effects are more dangerous. Rarely, especially if taken at higher than recommended doses or with alcohol, sleep aids have been known to cause people to walk or even drive during sleep and to cause severe allergic reactions.

Newer sleep aids can be used for longer periods of time without losing effect, becoming habit-forming, or causing withdrawal. They are also less dangerous if an overdose is taken.

Benzodiazepines are the most commonly used sleep aids. Some benzodiazepines (such as chlordiazepoxide, diazepam, flurazepam, and nitrazepam) are longer acting than others (such as temazepam and triazolam). Doctors try to avoid prescribing long-acting benzodiazepines for older people. Older people cannot metabolize and excrete drugs as well as younger people. Thus for them, taking these drugs may be more likely to cause daytime drowsiness, slurred speech, and falls.

Other useful sleep aids are not benzodiazepines but affect the same areas of the brain as benzodiazepines. These drugs (eszopiclone, zaleplon, and zolpidem) are shorter acting than most benzodiazepines and are less likely to lead to daytime drowsiness. Older people appear to tolerate these drugs well. Zolpidem also comes in a longer-acting (extended-release, or ER) form and a very short acting (low-dose) form. Ramelteon, a newer sleep aid, has the same advantages as these shorter-acting drugs. In addition, it can be used longer than benzodiazepines without losing its effectiveness or causing withdrawal symptoms. It is not habit-forming and does not appear to have overdose potential. Ramelteon affects the same area of the brain as melatonin (a hormone that helps promote sleep) and is thus called a melatonin receptor agonist. Doxepin, used as an antidepressant when given in high doses, is an effective sleep aid when given in very low doses.

Some antidepressants (such as paroxetine, trazodone, and trimipramine) can relieve insomnia and prevent early morning awakening when they are given in lower doses than those used to treat depression. These drugs may be used in the rare instances when people who are not depressed cannot tolerate other sleep aids. However, side effects, such as daytime sleepiness, can be a problem, especially for older people.

Nonprescription sleep aids: Some sleep aids are available without a prescription (over-the-counter, or OTC), but an OTC sleep aid may be no safer than a prescription sleep aid, especially for older people. OTC sleep aids contain diphenhydramine or doxylamine, both antihistamines, which may have side effects, such as daytime drowsiness or sometimes nervousness, agitation, falls, and confusion, especially in older people (see Over-the-Counter Drugs: Older People).

OTC sleep aids should not be taken for more than 7 to 10 days. They are intended to manage an occasional sleepless night, not chronic insomnia, which could signal a serious underlying problem. If these drugs are used a long time or stopped abruptly, they may cause problems.

Melatonin (see Medicinal Herbs and Nutraceuticals: Melatonin) is sometimes used to treat insomnia, especially in older people, who may have a low level of melatonin. It may be effective when sleep problems are caused by consistently going to sleep and waking up late (for example, going to sleep at 3 am and waking up at 10 am or later) —called delayed sleep phase syndrome. To be effective, melatonin must be taken when the body normally produces melatonin (the early evening for most people). Otherwise, melatonin can worsen sleep problems. Use of melatonin is controversial. It appears to be safe for short-term use (up to a few weeks), but the effects of using it for a long time are unknown. Also, melatonin products are unregulated, and thus purity and content cannot be confirmed.

Many other medicinal herbs and dietary supplements, such as skullcap and valerian, are available in health food stores, but their effects on sleep and side effects are not well understood.

Because sleep patterns deteriorate as people age, older people are more likely to report insomnia than younger people. As people age, they tend to sleep less and to awaken more often during the night and to feel sleepier and to nap during the day. The periods of the deep sleep that is most refreshing become shorter and eventually disappear. Usually, these changes alone do not indicate a sleep disorder in older people.

Older people who have interrupted sleep can benefit from regular bedtimes, lots of exposure to light during the day, regular exercise, and less napping during the day (because napping may make getting a good night's sleep even harder).

Many older people with insomnia do not need to take sleep aids. But if they do, they should keep in mind that these drugs can cause problems Thus, caution is required.

  • Poor sleep habits, stress, and conditions that disrupt people's internal sleep-wake schedule (such as shift work) cause many cases of insomnia and excessive daytime sleepiness.
  • However, sometimes the cause is a disorder, such as obstructive sleep apnea or a mental disorder.
  • Evaluation in a sleep laboratory, including polysomnography, is usually recommended when doctors suspect the cause is obstructive sleep apnea or another sleep disorder, when the diagnosis is uncertain, or when general measures do not help.
  • If insomnia is mild, general measures, such as following a regular sleep schedule, may be all that is needed.
  • If insomnia interferes with daily activities and general measures are ineffective, taking a sleep aid for up to a few weeks may help.
  • Sleep aids are more likely to cause problems in older people.

Last full review/revision January 2013 by Karl Doghramji, MD

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