Narcolepsy is a chronic
neurological disorder involving the loss of the brain's ability to regulate sleep-wake cycles. Symptoms include
excessive daytime sleepiness, comparable to how people who don't have narcolepsy feel after 24–48 hours of sleep deprivation, as well as disturbed sleep which often is confused with
insomnia. Another common symptom of narcolepsy is
cataplexy, a sudden and transient episode of muscle weakness accompanied by full conscious awareness, typically (though not necessarily) triggered by emotions such as laughing, crying, terror, etc. affecting roughly 70% of people who have narcolepsy.