Excessive daytime sleepiness. Narcoleptics may find it impossible to stay awake and often have uncontrollable sleepiness during the day..
Abnormal REM sleep. People with narcolepsy enter the REM, or dream, phase of sleep right after falling asleep, whereas most people take about 90 minutes to enter the REM phase.
Hypnagogic hallucinations. Some people with narcolepsy experience vivid, sometimes frightening, visual or auditory sensations while falling asleep or upon awakening.
Cataplexy. People with narcolepsy often have a sudden loss of muscle control while awake, usually experienced during strong emotion such as anger, grief, or while laughing.
Sleep paralysis. Sleep paralysis is the inability to move or talk at the beginning or end of sleep. About 25 to 50% of narcolepsy sufferers experience sleep paralysis.
Nighttime wakefulness. People with narcolepsy may have periods of wakefulness at night. This disrupted nighttime sleep adds to daytime sleepiness.
