Narcolepsy is a chronic neurologic disorder that involves loss of brain's ability to regulate sleep and wake cycles normally. People having narcolepsy frequently sleep during the day as compared to those people who don't suffer from it. These sudden attacks of sleep can occur during any type of activity and at any time of the day. A normal sleep pattern involves the early stages of sleep then followed by deeper sleep stages and ultimately rapid eye movement (REM) sleep. In narcoleptic people, REM
sleep occurs almost immediately in sleeping cycle and periodically during the waking hours.
Narcolepsy normally starts between ages of 15 and 25, but can become obvious at any age. In many cases, narcolepsy remains undiagnosed and hence untreated.