Diseases & Conditions


Narcolepsy is caused by the brain's inability to regulate sleep-wake cycles normally. The main features of narcolepsy are fatigue and cataplexy. It is often associated with sudden sleep attacks, insomnia, dream-like hallucinations and a condition called sleep paralysis. Symptoms usually begin when patients are between 10 and 20 years old. The main symptom of narcolepsy is excessive daytime sleepiness.

Symptoms of narcolepsy

Excessive daytime sleepiness

People with excessive daytime sleepiness are tired during the day even when they have had a full night's sleep. Sleepiness may occur during many different activities, including talking with others, eating dinner or driving. The sleepiness is difficult to prevent and may vary over the course of the day. After a short nap, people will feel alert, but the sleepiness usually returns after one or two hours.


Cataplexy is a sudden loss of muscle tone, usually triggered by emotional stimuli such as laughter, surprise or anger. It may involve all muscles and may result in collapse. It may only affect certain muscle groups and may result in slurred speech, buckling of the knees or weakness in the arms. Consciousness is maintained throughout the episode, but the patient is usually unable to speak.

Hypnagogic hallucinations

A hypnagogic hallucination is an experience of the transitional state from wakefulness to sleep or waking up. The patient has bizarre, often frightening dream-like experiences that incorporate his or her real environment.

Sleep paralysis

Sleep paralysis is a phenomenon in which a person temporarily experiences the inability to move during sleep-wake transitions. Sleep paralysis may last for a few seconds to several minutes and may accompany hypnagogic hallucinations.

What causes narcolepsy?

Narcolepsy affects both males and females and develops with age. Symptoms usually first develop in adolescence or young adulthood and may remain unrecognized as they gradually progress. The instance of a familial connection with narcolepsy is quite small but a combination of genetic and environmental factors may be the root of this sleep disorder. Recent studies suggest that people with narcolepsy with cataplexy often are missing a substance called hypocretin.


In order to make a determination of narcolepsy, your physician will ask you for a complete medical and family history and may refer you to our Sleep Disorders Center for evaluation. You should keep a sleep diary as well as a record of your symptoms and their severity for at least a week or two. Bring this information with you when you visit your sleep physician.

The following tests can help determine if you have Narcolepsy:


You may be referred to our Sleep Disorders Center for an overnight stay to monitor your sleep. Data is recorded about your sleep that will let the sleep physician make a diagnosis.

Multiple sleep latency test

This test takes place in our Sleep Disorders Center where you take series of naps at set times during the day. Data is recorded on how quickly you fall asleep.

Hypocretin level measurement

In rare cases, the level of hypocretin is measured in a sample of cerebrospinal fluid. This requires a lumbar puncture (spinal tap).

Treatment for narcolepsy

There is currently no widely-accepted cure for Narcolepsy but symptoms can be alleviated to the point of near-normal functioning in many patients.

Behavioral therapy

Behavioral therapies may help control symptoms, including taking three or more scheduled naps throughout the day. Patients should also avoid heavy meals and alcohol, which can disturb or induce sleep.


Counseling is very important for people with narcolepsy. The particular symptoms of this disorder are not widely understood by the general public and this may cause patients to feel uncomfortable, alienated, or depressed. The disease can also be quite frightening and the fear of falling asleep inappropriately often significantly alters life for people with narcolepsy.


In treating narcolepsy, physicians typically prescribe stimulants to improve your alertness and diminish excessive daytime sleepiness.

Antidepressants are also often used to treat cataplexy, hypnagogic hallucinations and sleep paralysis.

© Copyright 2017 Cleveland Clinic Abu Dhabi. All rights reserved.

This information is provided by Cleveland Clinic Abu Dhabi, part of Mubadala Healthcare, and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition.

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