Causes

Research continues to determine the cause of narcolepsy. Genetics and some sort of trigger, such as a virus, may affect brain chemicals and contribute to the disorder.

The normal process of falling asleep begins with a phase called non-rapid eye movement (NREM) sleep. During this phase, your brain waves slow down considerably. After an hour or two of NREM sleep, your brain activity picks up again, and REM sleep begins. Most dreaming occurs during REM sleep.

In narcolepsy, however, you suddenly fall into REM sleep without first experiencing NREM sleep and at abnormal times, such as during the day. Also, some of the aspects of sleep that normally occur only during REM sleep, such as sudden lack of muscle tone, sleep paralysis and vivid dreams, occur at other times during sleep in people with narcolepsy.

Narcolepsy affects males and females equally and occurs in all racial and ethnical groups. The condition may run in families. A small percentage of people with narcolepsy have a close relative with the disease.

See your doctor if you experience excessive daytime sleepiness that seriously disrupts your personal or professional life.

Narcolepsy - Daytime sleepiness > 1 > 2 > 3 > 4