More than 100 disorders of sleeping and waking have been identified, according to the National Institutes of Health. They may fall into one of the following categories:
Dyssomnias. Disturbances in the amount, timing or quality of sleep resulting in excessive daytime sleepiness or insomnia. Common dyssomnias include:
Insomnia. Condition of inadequate or poor sleep that may include difficulty falling asleep, waking up frequently during the night with difficulty falling back asleep, waking up too early in the morning or unrefreshing sleep. This is the most common type of sleep disorder.
Sleep apnea. Sleep disorder that causes breathing to become shallow or stop while sleeping. Each pause in breath usually lasts 10 to 20 seconds. Pauses can occur 20 to 30 times in an hour. This is the second most common sleep disorder. Left untreated, sleep apnea can be life-threatening. Excessive daytime sleepiness can cause people to fall asleep at inappropriate times, such as while driving. Sleep apnea also appears to increase a person's risk of numerous health conditions including high blood pressure (hypertension), heart attack, stroke and diabetes.
Hypersomnia. Excessive daytime sleepiness after adequate nighttime sleep.
Restless legs syndrome (RLS). Sleep disorder characterized by unpleasant sensations in the legs that are described as creeping, crawling, tingling, pulling or painful.
Narcolepsy. Chronic sleep disorder characterized by excessive and overwhelming daytime sleepiness and short “sleep attacks,” even after adequate nighttime sleep. About 250,000 Americans have narcolepsy, according to the National Center on Sleep Disorders Research. Its cause is unknown.
Periodic limb movement disorder (nocturnal myoclonus). Characterized by periodic episodes of repetitive jerking and kicking during sleep.
Circadian rhythm sleep disorders. Involves disruption of the body's natural sleep cycle. Common examples include jet lag (traveling quickly across numerous time zones) and sleep problems associated with shift work. Other examples: delayed sleep phase disorder, in which people go to bed and wake up at least two hours later than is desired, and advanced phase sleep disorder, in which people fall asleep and wake up several hours earlier than is desired.
Parasomnias. Disorders that involve abnormal behavioral or physiological events during sleep. They involve partial arousal or interference with sleep stage transition. Examples include:
Arousal disorders. Disorders that involve partial arousal, such as sleepwalking and night terrors, which are characterized by sudden arousal from sleep and increased pulse and breathing rate. They occur during the first third of the sleep cycle.
Sleep-wake transition disorders. Disorders that interfere with sleep stage transition. Examples are sleep talking, nocturnal leg cramps, sleep starts (sudden contraction in a leg, sometimes an arm or the head, at the start of sleep) and rhythmic movement disorder (consists of recurrent head banging, head rolling and body rocking).
Disorders associated with rapid eye movement (REM) sleep. Some examples are nightmares (frightening dreams that occur during REM sleep and are associated with increased pulse and rate of breathing, profuse sweating and arousal) and REM sleep behavior disorder (patients act out dreams that are vivid, intense, action-packed and violent).
Other parasomnias. These include teeth grinding (bruxism), bedwetting (enuresis) and sudden infant death syndrome (SIDS).
Sleep disorders associated with medical or psychiatric conditions. They include:
Sleep disorders associated with psychiatric conditions. Anxiety, depression, psychosis and many other psychiatric disorders can result in excessive sleepiness or insomnia.
Sleep disorders associated with neurological disorders. Common examples include headaches, dementia (progressive loss of intellectual function) and Parkinson's disease.
Sleep disorders associated with other medical disorders. Common examples include alcoholism, peptic ulcers, gastroesophageal reflux disease (GERD), asthma, hay fever, chronic obstructive pulmonary disease (COPD), chronic fatigue syndrome and chronic pain (e.g., fibromyalgia).
Proposed sleep disorders. Sleep problems for which there is insufficient information to establish them as distinct disorders. Common examples include:
Short sleepers. People who sleep less than 75 percent of the sleep time typically required for their age group, but who experience no negative impacts.
Long sleepers. People who routinely sleep more than 10 hours a night.
Fragmentary myoclonus. Brief, involuntary jerks or twists during sleep.
/doctor_89.jpg "ulcerative colitis tips")