Merck Manual

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Quick Facts



The Manual's Editorial Staff

Last full review/revision May 2020| Content last modified May 2020
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What is narcolepsy?

Narcolepsy is a disorder in which you fall asleep over and over, or are very sleepy, during the day. Along with the sleepiness, you may have sudden attacks of muscle weakness.

  • Narcolepsy doesn't affect your health, but it can cause problems for you at school or work

  • You have a higher chance of having a car crash or other accident

  • You may lose motivation, have trouble paying attention, or become depressed

  • Doctors test for narcolepsy with special sleep tests done in a sleep lab

  • Medicines can help you stay awake and control other symptoms

What causes narcolepsy?

People with narcolepsy don't have a normal sleep pattern. Brainwave patterns that should occur only during dreams may come on while you're awake.

Doctors aren't sure what causes narcolepsy. But it does seem to run in families. Some people may have a chemical imbalance in their brain.

What are the symptoms of narcolepsy?

Symptoms usually begin when you're a teen or young adult. They can include:

  • Falling asleep suddenly, without meaning to (sleep attacks)

  • Falling asleep during a meeting, or while driving or eating

  • Limpness or sudden muscle weakness, often caused by feeling a sudden emotion such as anger, surprise, or laughter

  • Not being able to move when falling asleep or waking up (sleep paralysis)

  • Vivid dreams

  • Seeing or hearing things that aren’t there when falling asleep or waking up

How can doctors tell if I have narcolepsy?

Doctors may have you fill out a questionnaire about your sleepiness. They may have you keep a sleep diary. In a sleep diary, you write down when you slept and how long. If doctors aren't sure what the problem is or how severe it is, they may send you to a sleep specialist. The specialist may do:

  • A sleep test

What are sleep tests?

Because you can't tell the doctor what's happening when you're asleep, doctors have equipment that can monitor you while you sleep. Sleep tests may be done:

  • At home in your own bed

  • In a sleep lab in the hospital or doctor's office

For the home test, you go to bed wearing sensors under your nose, around your chest, and on your finger. A small device attached to the sensors records your breathing patterns and oxygen levels. It sends the information to the sleep doctor.

For the sleep lab test, you'll sleep overnight in the lab. This test uses more sensors. For example, sensors monitor your brain waves and eye muscle movements. Also, a sleep technician watches you sleep using a video camera that records all your movements and breathing. People worry that they won't be able to sleep in the lab wearing all the sensors. But most people sleep no worse than they do at home.

How do doctors treat narcolepsy?

There's no cure for narcolepsy, but treatment helps many people live normally. Doctors will have you:

  • Get enough sleep at night

  • Avoid alcohol, smoking, and certain medicines that affect sleep

  • Take a short nap (less than 30 minutes) each day at the same time

  • Take stimulant medicines to keep you awake

  • Sometimes, take certain antidepressants that help prevent sudden muscle weakness and sleep paralysis

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
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