9 Most Common Sleep Disorders

By: DiscoveryHealth.com writers

Getting Enough Sleep Image Gallery Sleep disorders often disrupt a peaceful night's slumber -- but they can also affect everyday life. See more sleep pictures.

Whether you have a sleep disorder and you're looking for sleep disorder information, or you're looking to find ways to counteract your sleep disorder, this sleep disorders primer will give you relevant sleep disorders information to help you get the good night's sleep you desperately need.

Lying in bed, waiting for sleep to come can be a bit like spending the night in a slow-motion hell. The clock seems not to move, each environmental sound, from a dripping faucet to the dog snoring at the foot of the bed, seems amplified, and insignificant daytime events can take on a menacing life of their own. Welcome to sleeplessness.


Sleep disorders, from insomnia to sleep apnea to sleep deprivation due to work schedules or caring for sick family members, take an enormous toll on sufferers and society at large. The National Commission on Sleep Disorders Research estimates that 40 million Americans suffer from chronic sleep disorders and another 20 to 30 million experience sleep problems intermittently. And since sleep disorders increase with aging, those suffering from chronic sleep disorders are expected to rise to 79 million and those suffering from intermittent problems to increase to 40 million by 2010, as the U.S. population ages.

The costs of sleep-related problems are staggering. The commission estimated direct costs of sleeplessness at $15.9 billion annually and another $100 billion or more in indirect costs, such as litigation, property destruction, hospitalization and death resulting from sleep disorders and sleep deprivation.

Sleep problems can be induced by overconsumption of caffeine or alcohol, may be a side effect of medications, or can develop as secondary effects of another illness, such as arthritis, or a bladder condition, or a psychological disorder such as depression. But in a large number of cases, primary sleep disorders are the cause of sleeplessness or disrupted sleep.

Although more than 200 sleep disorders centers exist in the United States, experts estimate that 95 percent of those suffering from sleep disorders go undiagnosed, suffering needlessly from conditions that could be treated.

On the following pages, you will find descriptions of the 9 most common sleep disorders.

1: Delayed Sleep Phase Disorder

People who suffer from delayed sleep phase disorder have an especially hard time waking up in the morning.
People who suffer from delayed sleep phase disorder have an especially hard time waking up in the morning.
Dougal Waters/Getty Images

What is it? When a person's biological clock gets out of sync with accepted norms, sleep disorders arise. In delayed sleep phase insomnia, the person falls asleep and awakens later than required for normal activities such as work and school. Once the person falls asleep, however, his or her sleep is restful and uninterrupted. Awakening at an acceptable time, even with an alarm clock, is extremely difficult. Resulting symptoms include daytime sleepiness, particularly in the morning; fatigue; impaired memory and concentration; low productivity, particularly in the morning.

How common is it? Relatively rare (fewer than 2 percent of those seeking help at sleep disorder clinics are diagnosed with it). It frequently begins during childhood and is most common during adolescence. These symptoms are also seen in people suffering from depression.


What's the treatment? Two therapies are used:

  • Chronotherapy—This technique re-sets the person's biological clock by having the person stay up and awaken three hours later each day over a several-day period until their sleep and awake times are in sync with others. During that time they cannot nap, and once they've changed their schedule they must maintain it even on weekends (varying it by no more than an hour) to prevent the return of the problem.
  • Light therapy—This technique uses bright lights (as bright as sunlight) for two hours in the morning and avoids bright light for several hours before bedtime to shift the sleep-wake cycle. Special light boxes for this purpose are available through medical supply sources and are similar to those used to treat people with seasonal affective disorder.

2: Advanced Sleep Phase Disorder

What is it? This condition, in which the person's biological clock shifts to earlier hours—typically falling asleep before 9 p.m. and awakening between 3 and 5 a.m. and failing to return to sleep.

How common is it? This condition occurs most often in older people. In fact, some doctors believe it is more a normal consequence of aging than a disorder.


What's the treatment? Light therapy is effective in helping people to delay their sleep phase. The person is administered bright light (through special light boxes purchased through medical supply sources. They are similar to those used to treat seasonal affective disorder) for two hours before bedtime, which helps to delay sleep, and avoided at other times.

3: Non-24-Hour Sleep-Wake Syndrome

Is your biological clock on a different schedule from the rest of the world?
Is your biological clock on a different schedule from the rest of the world?
James Darrell/Photodisc/Getty Images

What is it? In this condition, the person's biological clock is 25 hours or longer, meaning that sleep and wake times are continually getting later.

How common is it? While this condition is rare, it seems to be more common in the blind than in the general population. One study showed that 75% of blind people complain of sleep problems. This may, in part, be due to the lack of light cues for waking and sleeping.


What's the treatment? Light therapy, in which the person is exposed to bright lights (as bright as sunlight) for two hours in the morning and avoids bright light for several hours before bedtime to shift the sleep-wake cycle, can be effective in patients with sight.

4: Jet Lag

What is it? Also known as time-zone change, jet lag is a disruption in sleep patterns following travel across time zones. It occurs because the traveler's internal "clock" is out of sync with the new time zone. Symptoms include difficulty falling asleep, difficulty arising, and disrupted sleep, all leading to daytime sleepiness, headache and general malaise.

How common is it? Jet lag is a common problem for travelers, and more common in those over 50 than in those under 30. Incidence varies depending on how many time zones and the direction of travel. When traveling westward, the traveler's internal clock is ahead of local time and the traveler typically tires early and awakens early. When traveling eastward, the traveler's internal clock is behind local time and the traveler typically falls asleep and awakens later than local time, and often is very sleepy during the day and particularly in the morning. These effects may be felt a day or two after travel. Frequent travelers can develop chronic jet lag symptoms.


What's the treatment? In general, traveling westward is easier than traveling eastward. A westward traveler can make up for about a 1.5-hour difference per day; an eastward traveler makes up about one hour per day. Adjusting to travel from Los Angeles to New York, for example, (a three-hour time difference) would take three days, but only two days on the return trip.

Some steps that can minimize the effects of jet lag are to adjust your sleep schedule to the new location during the days preceding your trip. Avoid alcohol and caffeine during your trip. Both can effect the quality of your sleep. Taking 5 mg. of melatonin at bedtime during the first few days following arrival may help in adjustment. Some prescription short-acting hypnotics can help relieve jet lag. Exercise and keeping well hydrated (with nonalcoholic or caffeine-free drinks) can also help in the adjustment to a new time zone. Light therapy, as used in advanced and delayed sleep disorders, may help in adjustment.

5: Shift Work

Take steps to help your body adjust to new work and sleep schedules.
Take steps to help your body adjust to new work and sleep schedules.
Paul Burns/Lifesize/Getty Images

What is it? The constant changing of sleep patterns among day, evening and night shifts has been linked to gastrointestinal and cardiovascular disease, increases in alcohol and tranquilizer use, and chronic sleep disorders.

How common is it? About 20 million U.S. workers, or about 22% of the workforce, are shift workers.


What's the treatment? Studies have found several methods can be effective in dealing with the impact of shift work on sleep. Using extremely bright lights during night-shift work and having a darkened bedroom at home can help adjustment. Exercise programs can help, and melatonin taken at bedtime can also be useful.

6: Obstructive Sleep Apnea

What is it? Obstructive sleep apnea is the temporary cessation of breathing due to the blockage of the upper airways during sleep. These brief obstructions result in many sleep interruptions each hour, which dramatically affects the quality of sleep. Since these awakenings are rarely remembered, sleep apnea sufferers are unaware of the source of their symptoms: daytime drowsiness, increased irritability or depression, decreased concentration and work productivity and even an increased number of traffic accidents. In fact, the excessive daytime drowsiness often is mistaken for narcolepsy. Loud, consistent snoring is a hallmark of obstructive sleep apnea.

How common is it? Sleep apnea is suffered by about 4% of men and about 2% of women.


What's the treatment? Overweight sufferers of obstructive sleep apnea benefit from weight loss. Avoidance of alcohol, narcotics and sedatives, which increase OSA incidence. Some patients respond to bedtime doses of protriptyline, a tricyclic antidepressant, and several other prescription medications. For most, however, other measures are needed. These include:

  • Position alarms, which sound if the person remains on his back (the position in which most apnea incidents occur) for more than 15 seconds. These and sewing tennis balls into the back of sleep shirts to prevent sleeping on the back are used.
  • Dental appliances that shift the jaw forward, expanding the airway.
  • Surgery to repair upper airway (tonsillectomy, adenoidectomy, or a resectioning of the uvula and soft palate).
  • Nasal Continuous Positive Airway Pressure (CPAP), a device that delivers a stream of air through a mask worn over the nose during sleep.

7: Narcolepsy

Narcolepsy can be dangerous -- especially if the person falls asleep behind the wheel.
Narcolepsy can be dangerous -- especially if the person falls asleep behind the wheel.
Adam Gault/Digital Vision/Getty Images

What is it? Narcolepsy is characterized by extreme, overwhelming sleepiness during the day. It is caused by a dysfunction of the brain mechanisms controlling sleep and waking. The person may suddenly fall asleep in midsentence, while at work, or behind the wheel of a car. Other symptoms of narcolepsy include the sudden loss of muscle tone while awake when surprised or upset (which can be severe enough to cause a collapse), and vivid hallucinations as the person is falling asleep, and sleep paralysis, a condition in which the body's normal paralysis of large muscles during REM sleep fails to end upon waking. Narcolepsy appears to run in families.

How common is it? Narcolepsy is rare, occurring in about 100,000 Americans. It may start in childhood but typically peaks in young adulthood.


What's the treatment? The symptoms of narcolepsy can be found in several other conditions, including obstructive sleep apnea, so accurate diagnosis is critical. Researchers now believe that narcolepsy is caused by the lack of receptors for the neurotransmitter hypocretin, which regulates the sleeping and waking states. Modafinil, which promotes alertness, has been shown to be effective in the treatment of narcolepsy. Behavioral changes that can help include avoiding caffeine nicotine and alcohol in the late afternoon or evening, regular exercise at least three hours before bedtime, and scheduling several short naps or one longer nap (20 to 40 minutes) each day.

8: Restless Leg Syndrome (RLS)

What is it? Restless Leg Syndrome is characterized by aching, itching, tingling and burning in the lower legs as the sufferer is falling asleep and typically requires him or her to get up and walk around for relief. The aching may also be accompanied by periodic limb movements that may continue for minutes or hours. It typically develops in middle age and appears to run in families. (Goetz: Textbook of Clinical Neurology, 1114)

How common is it? RLS occurs in about 2 to 5 percent of adults.


What's the treatment? Restless leg syndrome responds to levodopa, a drug also used to treat Parkinson's disease, and several other medications. Symptoms may be reduced by avoiding or reducing caffeine and alcohol and establishing a regular exercise program.

9: Sleepwalking

The stereotypical image of a sleepwalker: arms outstretched, eyes closed.
The stereotypical image of a sleepwalker: arms outstretched, eyes closed.
Image Source Black/Getty Images

What is it? Sleepwalking, which is most common in children, occurs during stage 3 and stage 4 sleep, the deepest levels, and is thought to be caused by a partial arousal from deep sleep. While the child's brainwaves are those of deep sleep, the sleepwalker moves as though awake. The episodes are typically brief—less than ten minutes—and usually occur during the first three hours of sleep. The sleepwalker usually has no recollection of the event in the morning.

How common is it? Sleepwalking occurs in more than 10% of children. Most children outgrow it. It appears to run in families. Sleepwalking episodes may be triggered by fever or some medications. Unpredictable sleep schedules, sleep deprivation and stress may also contribute to sleepwalking episodes.


What's the treatment? The child's safety during these episodes is of primary concern. Parents should ensure that doors and windows are locked and that no objects are left out that could cause falls or other injuries. When a child is sleepwalking, gently guide the child back into bed. Don't try to awaken him.

Hypnosis can be an effective treatment. Medications such as benzodiazepine or tricyclic antidepressants at bedtime can also be effective, but rebound episodes often occur when the medication is stopped.

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