Narcolepsy is a neurological condition most characterized by Excessive Daytime Sleepiness (EDS), in which a person experiences extreme tiredness, possibly culminating in falling asleep during the day at inappropriate times, such as at work or school. A narcoleptic will most probably experience disturbed nocturnal sleep, which is often confused with insomnia, and disorder of REM or rapid eye movement sleep. It is one of the dyssomnias. Cataplexy, a sudden weakness in the motor muscles, is also common and can result in the person falling and effectively being paralyzed for a period of time. Some patients with narcolepsy only have symptoms of cataplexy when they first visit their doctor.