Encyclopedia Home / S / Sleep Disorders - HealthCentral Encyclopedia

Sleep Disorders

  • Definition

    sleep disorders vary in nature and degree. The three major sleep disorders are dyssomnias (insomnia), hypersomnia (disorders of excessive sleepiness) and parasomnias (abnormal behaviors during sleep).


    Sleep consists of two distinct states: REM (rapid eye movement) sleep and NREM (non-REM) sleep. Dreaming occurs mostly in REM sleep.

    Sleep is a cyclic phenomenon, with four or five REM periods during the night, which accounts for about 25 percent of the total night’s sleep.

    Examples Of Sleep Disorders


    Insomnia, the sense of not getting enough sleep to awake refreshed, affects 20 to 40 percent of all adults in the course of any year. Although insomnia has myriad causes, it can roughly be divided into three categories: predisposing, precipitating and perpetuating.

    Predisposing factors are the built-in characteristics of a person that make him or her vulnerable. Tense or driven people whose heads are brimming with plans or worries can easily lose sleep. Others with severe depression often cannot sleep through the night. In manic disorders, sleeplessness may be important early sign of impending mania in bipolar patients. A few have neurologic or other conditions that affect them mainly at night - restless legs syndrome (for example) or the involuntary twitching of leg muscles (nocturnal myoclonus).

    Precipitating factors are events in life that trigger a period of disturbed sleep. Stresses that precipitate insomnia may include an increase in responsibilities, the loss of a loved one, hospitalization or acute pain, to name a few. An abrupt alteration of schedule, resulting from a change of shift at work or jet lag, can also provoke insomnia.

    Perpetuating factors are behaviors that help to maintain sleeplessness once it has begun. These include irregular sleep habits and the use of drugs. Abuse of alcohol may cause or be secondary to the sleep disturbance. Heavy smoking (more than a pack a day) causes difficulty in falling asleep. When sleeping pills help, it is mainly with the precipitating causes of insomnia and only then for a relatively brief period of time.

    Short-term or transient insomnia is seen in people who have no history of sleep disturbances and who have a fairly obvious precipitating factor. Taking sleeping pills for a short period of time (perhaps a few days) may be helpful in such cases, and there is little controversy about prescribing them to help people through a crisis. However, chronic insomnia (defined as three weeks or more of almost nightly sleep difficulty) is rarely helped by drugs.

    Early Awakening

    Waking too early may represent a rebound from use of alcohol at bedtime or even from certain types of sleeping pills. It is also a symptom of depression. Some people sink into depression gradually, and feeling blue eventually becomes a chronic way of living. Others focus on poor sleep, telling themselves and others, "Life would be much better if only I could get a decent night's sleep."

    Advanced Sleep Phase Syndrome

    The tendency to be early to bed and early to rise increases as we grow older. Most persons adapt successfully but some of us find that our bodies say, "It's bedtime," earlier than we desire – often well before 9 p.m. Known as advanced sleep phase syndrome (or ASPS) this problem can wreck havoc with social life. Most persons with ASPS try numerous strategies to help them stay awake. Even if they succeed in pushing bedtime later, they may not be able to sleep any later because their body clocks still awaken them in the early morning hours.

    It is important to note that age-related changes in normal sleep include an increase in wakeful periods during the night. These normal changes, early bedtimes and daytime naps, may play a role in the increased complaints of insomnia among older persons.

    sleep apnea

    The word "apnea" means the absence of breathing. During sleep, our breathing changes with the stage or depth of sleep. Some individuals stop breathing for brief intervals, however, when these episodes of apnea become more frequent and last longer, they can cause the body's oxygen level to decrease, which can disrupt sleep. The patient may not fully awaken, but is aroused from the deep restful stages of sleep, and thus feels tired the next day.

    There are two main types of sleep apnea which may occur together.

    The most common is obstructive sleep apnea, during which, breathing is blocked by a temporary obstruction of the main airway, usually in the back of the throat. This often occurs because the tongue and throat muscles relax, causing the main airway to close. The muscles of the chest and diaphragm continue to make breathing efforts, but the obstruction prevents any airflow. After a short interval lasting seconds to minutes, the oxygen level drops, causing breathing efforts to become more vigorous, which eventually opens the obstruction and allows airflow to resume. This often occurs with a loud snort and jerking of the body, causing the patient to arouse from deep sleep. After a few breaths, the oxygen level returns to normal, the patient falls back to sleep, the muscles of the main airway relax and the obstruction occurs again. This cycle is then repeated over and over during certain stages of sleep. Most people with obstructive sleep apnea snore suggesting that their main airway is already partly obstructed during sleep, but not all people who snore have obstructive sleep apnea.

    A less common form of sleep apnea is central sleep apnea, so named because the central control of breathing is abnormal. This control center lies in the brain, and its function can be disrupted by a variety of factors. There is no obstruction to airflow. The patient with sleep apnea stops breathing because the brain suddenly fails to signal the muscles of the chest and diaphragm to keep breathing. These patients do not resume breathing with a snort and body jerk, but merely start and stop breathing at various intervals. Although the mechanism is different than obstructive sleep apnea, sleep is still disturbed by the periodic decreases in oxygen, and the patients suffer from the same daytime symptoms. Some patients may suffer from a combination of the two causes of apnea, a disorder which is called mixed-sleep apnea.

    Sleep apnea should be suspected in individuals who are noted to have excessive daytime sleepiness and other symptoms described above, especially if they are known to snore and have a restless sleep. Commonly, these patients have exhibited loud snoring for many years, more often are male, and note that the daytime sleepiness has become a progressive problem over many months. Less commonly, they may be bothered by bedwetting or impotence. The sleep problems are often aggravated by alcohol or sedative medications. They are also more readily noticed by the patient's family and friends, especially the bed partner.


    narcolepsy is a chronic sleep disorder, characterized by excessive sleepiness and accompanied by a series of auxiliary symptoms, typically beginning in adolescence or young adulthood. It affects both sexes approximately equally. The principal symptoms are excessive daytime sleepiness (EDS), cataplexy (loss of muscle tone), hallucinations, sleep paralysis and disrupted nighttime sleep. Doctors also diagnose narcolepsy by measuring how quickly the patient falls asleep and how often rapid eye movements are present at or near the onset of sleep.

    Narcolepsy is a lifelong illness. There is no known cure and no report of lasting remission has been confirmed. Typically, symptoms (usually EDS) first become noticeable between the ages of 10 and 30. Symptoms are subtle at first, but become increasingly severe over the years. Narcolepsy may be treated with daily administration of a stimulant (e.g. dextroamphetamine sulfate).

    Cataplexy is an abrupt loss of voluntary muscle tone, usually triggered by emotional arousal. Attacks can range in severity from a brief sensation of weakness to a total collapse, lasting several minutes. Hallucinations are intense, vivid, sometimes accompanied by frightening auditory, visual and tactile sensations, and occur on just awakening or falling asleep.

    (Imipramine has been effective for cataplexy, not narcoplexy.)


    Your physician will take a complete medical history, perform a physical exam and may suggest additional tests, including sleep studies.


    Treatment varies, depending on the specific sleep disorder, but may include psychologic strategies as well as medications.

    Good sleeping habits

    • Go to bed only when sleepy.
    • Sleep only in the bedroom.
    • If still awake after 20 minutes, leave the bedroom and return when sleepy.
    • Get up at the same time each morning regardless of the amount of sleep during the night.
    • Discontinue caffeine and nicotine in the evening (if not completely).
    • Establish a daily exercise program.
    • Avoid alcohol because it may disrupt continuity of sleep.
    • Limit fluid intake in the evening.
    • Learn and practice relaxation techniques.


    Sleeping pills have limited uses. They may help, for example, during an overnight airplane ride, and when taken in a crisis, they might prevent an acute problem from turning into chronic insomnia. But doctors and patients have come to learn that long-term use has more risks than benefits. Today, most insomnia patients are not given sleeping pills, and most insomnia patients who do take drugs use them briefly. Long-term users usually have either a generalized anxiety disorder or a chronic physical illness exacerbated by anxiety, such as arthritis or heart disease.

    The drugs used to induce drowsiness (hypnotics and sedatives) are often the same as those used to relieve anxiety (anxiolytics). Today, the most popular anxiety relievers and sleep inducers are the benzodiazepines, which enhance the effect of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). The benzodiazepines used as sleeping pills include diazepam (Valium) and temazepam (Restoril). They may become ineffective within a few weeks because of tolerance.

    Zolpidem (Ambien) is a short-acting drug that is not a benzodiazepine but has a similar mechanism of action. Preparations containing antihistamines are sold over the counter under such names as Nytol and Sominex. They are fairly safe and may be useful, but tolerance may develop quickly. For depression associated with disturbed sleep, sedative antidepressant drugs such as amitriptyline (Elavil) and trazodone (Desyrel), are often prescribed. Antipsychotic drugs (neuroleptics) may provoke sleep in anxious, hallucinating manic or schizophrenic patients.

    It is very important that you inform your physician of any and all medications you are taking, including over-the-counter and prescribed medications.


    What kind of sleep disorder is it? How is it diagnosed?

    If a person doesn't get enough sleep does it affect the body?

    What over the counter sleeping aids do you recommend?

    How long can a person take sleeping pills without adverse reactions?

    Will you be prescribing any medication? What are the side effects?

    Other than the measures outlined in this report, are there other proven methods for getting to sleep and staying asleep?