Sleep Disorders

Sleep disorders hinder the normal ability to fall asleep, stay asleep or get restful sleep at the socially prescribed times. Sleep disorders also include any involuntary, abnormal sleep behaviors that interfere with a person's day-to-day functioning. Lack of restful sleep can lead to poor work performance, accidents and chronic illness.National Sleep Foundation: How Much Sleep Do We Really Need? (Page 2)

The inability to fall asleep or stay asleep is known as insomnia. Disorders of sleep timing, such as jet lag, are called circadian rhythm sleep disorders and generally only prevent a person from sleeping at certain times of the day or night. One of the more common circadian rhythm disorders is delayed sleep phase syndrome, a consistently delayed sleep pattern despite attempts to sleep during the appropriate hours. Restless leg syndrome and periodic limb movement disorder can also disrupt or prevent sleep

Some sleep disorders primarily cause difficulties with staying awake during the day. Sleep apnea is a disorder of nighttime breathing that causes sufferers to snore loudly and prevents them from getting deep and restful sleep. Even though they often sleep eight or more hours at night, they feel unrested and sleepy during the day.

Narcolepsy causes uncontrollable "sleep attacks" during the day, where the sufferer suddenly falls asleep at inappropriate times.

Parasomnias are disorders that cause a person to temporarily get stuck in between wakefulness and sleep. The most extreme of these is night terrors, a condition where the sleeper is in a panicked state, often screaming and moving about, but unable to regain normal consciousness.

Parasomnias also include other disorders of sleep paralysis such as sleepwalking, talking or eating, tooth-grinding (bruxism) and bedwetting.