Narcolepsy is a neurological disorder that affects the nervous system leading to the loss of the brain's ability to regulate sleep-wake cycles. It is characterized by diurnal somnolence and episodes of short duration sleep. Symptoms include repeated daytime sleepiness , similar to how people who do not 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, frequently triggered by emotions such as laughing, crying, terror, etc. affecting almost 70% of people who have narcolepsy. Recent laboratories research on hypocretins (oroxins) has led to a greater understanding of this debilitating condition. The goal of this minireview is to describe briefly the etiology of narcolepsy.