Definition

Narcolepsy is a neurological disorder characterized by uncontrollable episodes of sleepiness during the day. Episodes can last from a few seconds to more than an hour and can significantly interfere with daily activities.

Description

People with narcolepsy often fall asleep suddenly, anywhere at any time, even in the middle of a conversation. They may sleep for just a few seconds or for up to a half hour, and then reawaken feeling alert until they fall asleep again. The condition affects one of every 2,000 Americans. Sleep apnea (difficulty in breathing while sleeping) is the leading cause of excessive daytime sleepiness. Narcolepsy is the second leading cause.

The attacks of sleepiness that are the hallmark of this condition may be mildly inconvenient or deeply disturbing. Some people continue to function during...