Narcolepsy

Narcolepsy is a chronic, or long-lasting, sleep disorder with no known cause. It affects the body's central nervous system, which is made up of nerves that carry messages from the brain to other parts of the body. When a person has narcolepsy, messages about when to sleep and when to be awake can get mixed up. This can cause a person to fall asleep when they do not want to, and often without any warning like feeling drowsy.

The desire to sleep can be overwhelming and hard to resist, and can happen to a person several times during the day. Night sleep may also be poor, broken up by waking up often during the night. If not controlled with medication, narcolepsy can cause serious problems in a person's personal, social, and work life. It can also limit a person's activities, such as driving a car, work, and exercising. Studies indicate that narcolepsy may run in families.