Narcolepsy is a chronic sleep disorder characterized by excessive sleepiness and sudden sleep attacks. It is classified into two types: type 1 and type 2. Both have the same leading symptom: excessive daytime sleepiness, while people with type 1 also suffer from cataplexy. The symptoms usually appear between 15 and 30 years of age. The pathophysiology underlying narcolepsy involves loss of hypocretin-producing neurons that have a major role in regulating sleep-wake cycle. The etiology of the neuronal death is not fully understood, yet it seems that it is about an autoimmune process triggered by an environmental factor. It is found that certain people have a genetic predisposition for developing narcolepsy. The pathophysiology of narcolepsy type 2 is unclear, but the hypocretin levels in the cerebrospinal fluid are generally normal and symptoms are less severe. The diagnosis is based on medical history, polysomnography, multiple sleep latency test and cerebrospinal fluid hypocretin level measurement. A specific therapy does not exist. Symptomatic treatment includes central nervous system stimulants and other drugs such as modafinil, armodafinil, pitolisant, sodium oxybate. Good sleep hygiene can also be helpful. The goal is to minimize sleepiness and frequency of cataplectic seizures, to improve sleep quality and maximize alertness during the day.