Narcolepsy is a chronic neurological disorder caused by the brain's inability to regulate the correct times for sleeping and the correct times to be awake. At various moments throughout the day, people with narcolepsy experience sudden urges to sleep. If the urge becomes overwhelming, they may do so for periods lasting from a few seconds to several minutes. The condition is profoundly disabling, interrupting life's basic day to day activities, including working, driving, even conversing with others. Narcolepsy affects about 1 in every 2,000 Americans.