Narcolepsy is usually caused by low levels of a neurotransmitter, called hypocretin, that helps you stay awake by keeping your brain from entering a deep state of sleep. Sometimes people have narcolepsy that is not caused by low hypocretin levels, but the reason for the condition is not known.
A combination of genetic, autoimmune, and environmental factors put some people at higher risk for narcolepsy. Narcolepsy may occur after an upper airway infection or, rarely, because of a head injury, sarcoidosis, a stroke, a tumor, or another medical condition.
Signs and symptoms include extreme daytime sleepiness; falling asleep without warning, called sleep attacks; difficulty focusing or staying awake; and waking often at night. Other common symptoms that occur when falling asleep or waking up are hallucinations and sleep paralysis, which is a feeling of being awake but unable to move for several minutes. Rarely, people who have narcolepsy may experience loss of muscle tone, called cataplexy, which occurs with strong emotions such as laughter. People who have narcolepsy usually feel refreshed after a brief nap or a full night’s sleep but become sleepy again soon after.
To diagnose narcolepsy, your doctor will consider your medical history, family history, physical exam, and test results. You may have an overnight sleep study, including a sleep test that looks at daytime naps to identify disturbed sleep or a quick onset of rapid eye movement (REM) sleep. Spinal fluid tests may show low levels of hypocretin. If your hypocretin levels are normal, your doctor may ask you to track your sleep habits in a sleep diary and may record information from special devices called actigraphs that track activity and rest periods throughout the day.
Treatment for narcolepsy combines medicines and behavior changes. Medicines used to treat narcolepsy include stimulants and modafinil to treat daytime sleepiness, sodium oxybate to treat daytime sleepiness and cataplexy, and sedatives to improve nighttime sleep. Daytime sleepiness often improves with enough good-quality sleep at night and scheduled naps during the day.
Even with treatment, people who have narcolepsy may still have daytime sleepiness and may experience depression. Talk to your doctor about safety issues, including the risk of car accidents. Therapy, education, and counseling may help you manage your symptoms.
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Learn about the following ways the NHLBI continues to translate current research into improved health for people with narcolepsy and other sleep disorders. Research on this topic is part of the NHLBI’s broader commitment to advancing sleep science and sleep disorders scientific discovery.
In support of our mission, we are committed to advancing narcolepsy research, in part through the following ways.
Learn about exciting research areas the NHLBI is exploring that are related to narcolepsy and how sleep affects health.
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