Medically Reviewed by Carol DerSarkissian, MD on November 15, 2021

What Is Narcolepsy?

Narcolepsy is a neurological disorder that affects your ability to wake and sleep. People with narcolepsy have excessive, uncontrollable daytime sleepiness. They may also suddenly fall asleep at any time, during any type of activity.

In a typical sleep cycle, we enter the early stages of sleep, then the deeper stages, and finally (after about 90 minutes) rapid eye movement (REM) sleep. People with narcolepsy go into REM sleep almost immediately in the sleep cycle and sometimes while they’re awake.

Type 1 narcolepsy comes with a sudden loss of muscle tone that causes weakness and makes you unable to control your muscles (cataplexy). Type 2 is narcolepsy without cataplexy.

In many cases, narcolepsy isn’t diagnosed and therefore isn’t treated..

Narcolepsy Symptoms

In REM sleep, we can dream and have muscle paralysis, which explains some of the symptoms of narcolepsy. Those symptoms may include:

  • Excessive daytime sleepiness (EDS): In general, EDS makes it harder to do everyday activities, even if you got enough sleep at night. The lack of energy can make it hard to concentrate. You have memory lapses and feel depressed or exhausted.
  • Cataplexy: This can cause problems ranging from slurred speech to total body collapse, depending on the muscles involved. It’s often triggered by intense emotions such as surprise, laughter, or anger.
  • Hallucinations: These delusions can happen at any time and are often vivid and frightening. They’re mostly visual, but any of the other senses can be involved. If they happen as you’re falling asleep, they’re called hypnagogic hallucinations. If they happen when you’re waking up, they’re called hypnopompic hallucinations.
  • Sleep paralysis: You may be unable move or speak while falling asleep or waking up. These episodes usually last a few seconds to several minutes.
  • Disrupted sleep: You might have a hard time staying asleep at night because of things like vivid dreams, breathing problems, or body movements.

Narcolepsy Causes

Experts don’t know what causes narcolepsy. They think it involves multiple things that come together to cause problems in your brain and disturb your REM sleep.

Scientists are getting closer to finding genes linked to the disorder. These genes control the production of chemicals in your brain that may signal sleep and awake cycles.

Some experts think narcolepsy may happen because your brain has a hard time making a chemical called hypocretin. They’ve also found problems in parts of the brain involved in controlling REM sleep.

Risk factors for narcolepsy include your age. Narcolepsy usually begins between the ages of 15 and 25, but it can show up at any age. If you have a family history of narcolepsy, your risk of getting it is 20 to 40 times higher.

Narcolepsy-Related Conditions and Behaviors

Some people with narcolepsy also have related problems, including:

  • Periodic limb movement disorder (PLMD): Your leg muscles move without your control many times during the night.
  • Sleep apnea: Your breathing often stops and starts while you sleep.
  • Automatic behavior: You fall asleep during a regular activity like driving, walking, or talking. You continue the activity while asleep and wake up with no memory of what you did.

Narcolepsy Diagnosis

Symptoms of narcolepsy can look like those of other health problems. Your diagnosis might involve:

  • Physical exam and medical history
  • Sleep records: Your doctor might ask you to keep track of your symptoms and when you’re sleeping for a couple of weeks.
  • Polysomnogram (PSG): This is done in a sleep disorder clinic or a sleep lab. It’s an overnight test that takes constant measurements while you’re asleep to record problems in your sleep cycle. A PSG can help reveal whether you go into REM sleep at unusual times in your sleep cycle. It can rule out other problems that might be causing your symptoms.
  • Multiple sleep latency test (MSLT): This is also done at a special clinic or lab. The test takes place during the day to measure your tendency to fall asleep and find out whether certain elements of REM sleep happen at unusual times during the day. You’ll take four or five short naps, usually 2 hours apart.

Narcolepsy Treatment

There’s no cure for narcolepsy. But treatments that can help ease your symptoms include:

Show Sources


National Sleep Foundation.

National Organization for Rare Disorders: “Narcolepsy.”

National Institute of Neurological Disorders and Stroke: “Narcolepsy Fact Sheet.”

Mayo Clinic: “Narcolepsy.”

St. Luke’s Hospital: “Narcolepsy.”

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