Major Sleep Disorders
Many sleep disorders are rare. For example, in 15 years of practice, Davila has treated only a few cases of recurrent hypersomnia, in which people have periods of extreme sleepiness that come and go. During an attack, a person may sleep up to 16-18 hours, rousing only to eat or use the bathroom. Episodes can last a few days or many weeks.
Insomnia: Insomnia may be a symptom of a sleep disorder, so people with this complaint may need a thorough evaluation, Shives says. But it can also be a sleep disorder by itself. Insomnia makes it difficult to fall asleep or stay asleep. Sleep quality may be poor, leaving people feeling unrefreshed when they awake.
Sleep apnea: This sleep disorder causes loud snoring, gasping, choking, pauses in breathing, and sudden awakenings. The person repeatedly stops breathing long enough to interfere with sleep; these pauses also temporarily decrease a person's oxygen supply. During the day, people with sleep apnea often feel very sleepy. Sleep apnea can raise the risk of high blood pressure, stroke, and heart attack.
Restless legs syndrome (RLS): RLS causes irresistible urges to move the legs while a person is lying down. The person may also feel creeping, crawling, burning, or painful sensations in the legs. In a related sleep disorder called "periodic limb movement disorder," repetitive jerking movements or twitching of the legs or arms during slumber lead to fragmented, unrefreshing sleep.
Parasomnias: Parasomnias, or abnormal behaviors during sleep, include sleepwalking, sleep-talking, head-banging, and night terrors that cause people to sit up, flail, and scream. In one type of parasomnia called "rapid eye movement behavior disorder," people may kick, punch, or wave their arms unintentionally (usually in response to a dream) while they're in REM sleep. This sleep disorder usually afflicts older men, according to Shives. It has also been linked to an increased risk of Parkinson's disease, she adds.
Narcolepsy: Narcolepsy's main symptoms are excessive sleepiness during the day or recurring "sleep attacks" that cause people to fall asleep uncontrollably during normal waking hours. Some people also have sudden spells of muscle weakness following emotional excitement and may fall to the ground. Some people with narcolepsy experience sleep paralysis, where they can't move when falling asleep or just waking up. Other symptoms include vivid dreams or hallucinations while falling asleep or waking up.