Narcolepsy is a chronic sleep disorder. It can be thought of as an intrusion of dreaming sleep (REM) into the waking state.

When a person has narcolepsy, messages to and from the brain about when to sleep and when to be awake do not function properly, causing overwhelming daytime drowsiness and sleep attacks.

If not controlled with medication, narcolepsy can lead to personal, social, and employment difficulties. It can stop people from driving or working and may cause a person to lose confidence in themselves and their desired activities.

The irresistible sleep attacks throughout the day can last for 30 seconds to more than 30 minutes, regardless of the amount or quality of prior sleep at night.

Narcolepsy is often misdiagnosed or diagnosed only years after symptoms first appear. This situation unfortunately can be detrimental to a person's physical and mental well-being.

Narcolepsy is not a mental illness and is not caused by stress.

Narcolepsy comes from the Greek word narke meaning stupor. It was first described in the 1880s by French physician Jean-Baptiste Edouard Gelineau.