As a disease, narcolepsy is not fatal but many of the characteristics of this condition are.
What is Narcolepsy?
Narcolepsy is a neurological disorder that affects the body's ability to regulate the sleep cycle. Unlike sleeping disorders such as apnea, narcolepsy does not cause or stem from restricted airway during sleep, so it is not considered a fatal disorder in itself. Instead, the accompanying factors make narcolepsy dangerous.
Cataplexy, the sudden loss of muscle control, often accompanies narcolepsy. Akin to seizures, cataplexy attacks can certainly be dangerous if they occur while you are in control of heavy machinery, sharp objects, and vehicles. Cataplexy often causes falls, sometimes resulting in serious injury.
Visual and auditory hallucinations are common, especially immediately upon waking. Vivid hallucinations can confuse and frighten you into potentially dangerous situations since it may be difficult for you to distinguish them from reality.
Excessive Daytime Fatigue
The overwhelming fatigue of narcolepsy may cause you to fall into "microsleep" during daily activities. During microsleep, the brain shuts down, but the body continues performing automatic behavior like brushing teeth or typing or even talking. These behaviors have become such routine that you don't need to think while doing them, so the brain takes advantage of the chance to rest for a few seconds. Just a few seconds, however, may be enough time for you to get in a car accident or plug in an appliance with wet hands. The National Highway Traffic Safety Administration estimates more than 1500 fatal car accidents each year are caused by drowsiness while driving.