Narcolepsy is a lifelong sleep disorder that makes you feel overwhelmingly tired, and in severe cases, have sudden uncontrollable sleep attacks. Narcolepsy can impact nearly every aspect of your life. It is dangerous because you can have excessive sleepiness or a sleep attack at any time of the day, in the middle of any activity including eating, walking or driving. Operating a vehicle with untreated narcolepsy can be very dangerous and some states even have laws against it.
Many people with narcolepsy do not know they have the sleep disorder. About one in 2,000 people have some form of narcolepsy. Narcolepsy may run in some families, but most cases are not genetic. The cause of narcolepsy is still unknown, but recent research suggests that many people with narcolepsy with cataplexy have low levels of the neurotransmitter hypocretin, a chemical that regulates arousal, wakefulness and appetite.