The Cleveland Clinic

Sleep Disorders: Parasomnias

Parasomnias are disruptive sleep-related disorders that can occur during arousals from REM sleep or partial arousals from Non-REM sleep.

Types of Parasomnias

Nightmares

Nightmares are vivid nocturnal events that can cause feelings of fear, terror, and/or anxiety. Usually, the person having a nightmare is abruptly awakened from REM sleep and is able to describe detailed dream content. Usually, the person having a nightmare has difficulty returning to sleep. Nightmares can be caused by many factors including illness, anxiety, the loss of a loved one, or negative reactions to a medication. Call your doctor if nightmares occur more often than once a week or if nightmares prevent you from getting a good night's sleep for a prolonged period of time.

Sleep terrors/night terrors

A person experiencing a night terror or sleep terror abruptly awakes from sleep in a terrified state. The person may appear to be awake, but is confused and unable to communicate. Night terrors last about 15 minutes, after which time the person usually lies down and appears to fall back asleep. People who have sleep terrors usually dont remember the events the next morning. Night terrors are similar to nightmares, but night terrors usually occur during deep sleep. People experiencing sleep terrors may pose dangers to themselves or others because of limb movements. Night terrors are fairly common in children aged three to five. This sleep disorder, which may run in families, also can occur in adults. Strong emotional tension and/or the use of alcohol can increase the incidence of night terrors among adults.