Narcolepsy is a sleep disorder that leads someone to fall asleep at odd times suddenly. Someone with narcolepsy may have abnormalities in the area of the brain that controls rapid eye movement (REM) sleep. This sleep disorder can make staying awake during the day difficult, causing problems in functionality. By reading the related topics below, you can learn more about this fairly rare sleep condition. You can also search by related topic to find out what causes narcolepsy, how it affects a person’s daily life and viable treatment options for this condition.