Life in Flashes

What is narcolepsy?

Narcolepsy is a neurological sleep disorder characterized by chronic, excessive attacks of drowsiness during the day, sometimes called excessive daytime sleepiness (EDS). Attacks of drowsiness may persist for only a few seconds or several minutes. These episodes vary in frequency from a few incidents to several during a single day. Nighttime (nocturnal) sleep patterns may also be disrupted.

Source: National Organization for Rare Disorders

Two Variations

Image by Ryan Moreno


NT1 is associated with the symptom of cataplexy, which is the sudden loss of muscle tone. NT1 was formerly known as “narcolepsy with cataplexy.”

Not all patients who are diagnosed with NT1 experience episodes of cataplexy. NT1 can also be diagnosed when a person has low levels of hypocretin-1, a chemical in the body that helps control wakefulness.



NT2 was formerly known as “narcolepsy without cataplexy.” People with NT2 have many similar symptoms as people with NT1, but they do not have cataplexy or low levels of hypocretin-1.

If a person with NT2 later develops cataplexy or low hypocretin-1 levels, their diagnosis can be reclassified as NT1. This change in diagnosis is estimated to occur in about 10% of cases.


What are the symptoms?



Excessive daytime sleepiness

Excessive daytime sleepiness is usually the first sign of narcolepsy. It can have a significant impact on everyday life.

Feeling drowsy throughout the day and struggling to stay awake makes it difficult to concentrate at work or school.

People with narcolepsy may be misjudged as being lazy or rude.