Narcolepsy is a chronic sleep disorder that involves the central nervous system. People with narcolepsy may have sleep attacks that come on without warning. Narcolepsy often shows up in younger people, but can also appear later in life. It can be diagnosed by a health care provider or a sleep specialist.
You may have any of the following symptoms:
Excessive daytime sleepiness (EDS), when you want to sleep all day long.
Sleep attacks that occur without warning and are hard to resist.
Cataplexy, a sudden loss of muscle control or tone. It is often triggered by stress or emotion, such as laughter, fear, or anger.
Sleep paralysis, a feeling of not being able to talk or move for a short time. It may occur when a person is falling asleep or waking up.
Hypnagogic and hypnopompic hallucinations, certain images, sensations, or sounds that occur when a person is falling asleep (hypnagogic), or waking up (hypnopompic).
Other symptoms, such as insomnia, fatigue, poor memory and concentration, or depression.
REM (rapid eye movement) is the dreaming portion of sleep. Usually, REM sleep begins after the first 90 minutes. For people with narcolepsy, REM sleep begins much sooner. This can make dreaming so vivid, it seems real. Many of the symptoms of narcolepsy are caused by the intrusion of REM sleep into wakefulness. During REM sleep, individuals are normally paralyzed. Waking out of REM sleep results in sleep paralysis. Cataplexy is caused by loss of muscle tone briefly, as would occur during REM sleep. The hallucinations on falling asleep or waking up are based on dreaming during REM sleep and awakening and seeing the dream ongoing with your eyes open.