Narcolepsy type 1

with cataplexy

Narcolepsy type 1 (NT1) is a long-lasting (chronic) hypersomnia sleep disorder of the brain (neurologic disorder).


  • Affects the brain’s ability to control sleep and wakefulness 
  • Causes excessive daytime sleepiness (EDS) — a strong daytime sleepiness or need to sleep during the day, even with enough sleep the night before 
  • Is sometimes called narcolepsy with cataplexy (a sudden and temporary episode of muscle weakness, usually triggered by strong emotions) 

NT1 is caused by problems with orexin, a chemical messenger for nerve cells (neurotransmitters).


  • Affects several systems in the body, including sleep-wake, appetite, energy levels, reward systems, thinking, and mood 
  • Helps with sleep-wake regulation (control) and promotes wakefulness during the daytime 

Most likely, an autoimmune process (where your immune system makes your body attack itself) leads to low orexin levels and causes problems with these body systems.

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What are the symptoms of NT1?

Common symptoms include:

  • EDS — Excessive daytime sleepiness
  • Cataplexy
  • Needed naps
    • Usually short and refreshing (restorative)
    • May be hard or impossible to avoid
  • Disrupted nighttime sleep
    • When you wake up many times in a night
    • You may not notice when this happens, but it can make your sleep less restful and you may wake up feeling tired and unrefreshed
    • Your sleep studies may show arousals (wake-ups) from sleep or a high number of shifts (changes) between different stages of sleep
  • Sleep-related hallucinations (or waking dreams) — Seeing, hearing, feeling, or smelling something that isn’t actually there while you’re falling asleep or waking up
  • Sleep paralysis — Inability to move or speak, which happens while falling asleep or waking up and lasts for a few seconds to minutes 
  • Brain fog — Feeling mentally sluggish or fuzzy, confused, forgetful, or unable to focus
  • Sleep attacks — Episodes when you fall asleep in places or at times you don’t want to
  • Fatigue
    • A lack of physical or mental energy
    • Feeling tired or exhausted

You don’t need to have all of these symptoms to be diagnosed with NT1, but you’ll have at least some of them.

To learn more about coping with some of these symptoms, visit Project Sleep’s web pages:

How do I know if I have cataplexy?

Episodes of cataplexy can be very different in how long they last and how intense they are. They may include:

  • Knees buckling
  • Jaw briefly becoming loose or limp
  • Eyelids and head drooping (this may look like sleep to others)
  • Falling down and being unable to move for several minutes

You won’t lose consciousness, but it may look to others like you passed out or fainted. These episodes are often triggered by strong emotions such as laughter. If you think you may have cataplexy, take notes about your episodes (and video if possible) to discuss with your doctor.

Watch this short BBC video “What is it like to have a cataplexy attack”: 

At what age do NT1 symptoms usually start?

Symptoms most often start in a person’s mid-to-late teens. However, they can start at any age. They may start suddenly or develop over time.

Symptoms may:

  • Happen every day, or a few days a week
  • Get worse or better over hours, weeks, months, or years

If you have NT1, you may have times when you can function (do daily activities such as work or school) well or well enough, and other times when you don’t function well at all. Even if you function well at times, your symptoms should be taken seriously.

How do NT1 symptoms compare to IH and NT2 symptoms?

Visit our web page: “Compare symptoms of idiopathic hypersomnia and narcolepsy types 1 and 2.”

How common is NT1?

Researchers estimate that narcolepsy in general (including both NT1 and NT2) happens in 1 in 2,000 people. It’s harder to know how many people have NT1, but researchers estimate 1 in every 5,000 people to 1 in every 3,333 people have it.

What’s it like to have NT1?

NT1 can greatly affect daily life:

  • The amount and timing of needed sleep can limit daily activities.
  • Cataplexy can be very distressing and also lead to falls.
  • Sleep-related hallucinations and paralysis can be very distressing.
  • NT1 can cause problems with thinking, working, and socializing. People with NT1 may have trouble doing their jobs, staying in school, having romantic relationships, and fully engaging with their friends and loved ones. 

These effects are especially true for people who aren’t taking medicines that work well. But even with medicines, people who have NT1 may struggle with these activities.

Stories from people living with NT1

While almost everyone with NT1 has EDS and cataplexy, not everyone has the other symptoms, and they can affect each person differently. Watch these videos to learn more:

How will doctors know if I have NT1?

Doctors will usually:

  1. Ask about your symptoms and medical history, sometimes using questionnaires
  2. Confirm from your history that you have cataplexy and daily EDS
  3. Do a complete physical exam and medical tests, including sleep studies, to make sure your EDS isn’t caused by something else

Common causes of EDS other than NT1 include: 

Testing for hypersomnia sleep disorders almost always includes a 2-part sleep study:

  1. An overnight sleep study measures several features of sleep and helps rule out other sleep problems such as sleep apnea. If you have cataplexy and REM sleep within 15 minutes of falling asleep, doctors can diagnose you with NT1 without doing the 2nd part of the sleep study.
  2. A daytime nap study called a Multiple Sleep Latency Test (MSLT) measures how long it takes you to fall asleep during 4 or 5 nap opportunities (chances to nap). The MSLT  is another chance to see if you have REM sleep within 15 minutes of falling asleep. Doctors will usually diagnose you with NT1 if you have all of these features:
    • Falling asleep in 8 minutes or less (on average across all nap opportunities) 
    • Two or more episodes of REM sleep within 15 minutes of falling asleep (including your overnight sleep study)

You may need to prepare during the weeks leading up to your sleep studies, and your doctor may recommend that you change or stop taking specific medicines. Ask for time off from school or work if your symptoms are likely to keep you from being able to function well while you prepare. This may happen if you need to: 

  • Get much more sleep than you usually do
  • Change from a shift work schedule to a normal schedule
  • Stop medicines that are helping your symptoms
    • You may need to slowly taper off some medicines, such as antidepressants, and it may  take longer for you to stop them before your sleep study and then get back up to a dose that works well for you after your sleep study

To learn more, visit our web pages: 

What if I don’t clearly have cataplexy?

The MSLT results doctors use to diagnose NT1 and NT2 are the same, so the results don’t help show which sleep disorder you have. Your symptoms, especially cataplexy, can help doctors tell the difference. If you don’t clearly have cataplexy, you may need to follow these steps to tell the difference between NT1 and NT2:

  1. Have a blood test for HLA-DQB1*06:02. If this blood test is negative, you most likely have NT2. If this test is positive, you may need step 2.
  2. Have a spinal tap to check orexin levels in your cerebrospinal fluid (CSF). If your orexin levels are low, you have NT1. If your orexin levels are normal, you most likely have NT2.

If you’re a person of African descent, you may be more likely to have narcolepsy without cataplexy and with low orexin levels. This is the form of NT1 needing these extra tests for correct diagnosis. Read our article “Differences in Hypersomnia Disorder Symptoms Among African Americans.” 

When should my doctor repeat my sleep studies?

Once your doctor diagnoses you with NT1, you usually don’t need to repeat sleep studies.

What can help my symptoms?

Visit our web pages:

Learn more

Visit our web page for doctors: “Diagnosis, classification, symptoms, and causes of hypersomnias.”

Published Jan. 19, 2024 |
Revised Jan. 30, 2024
Approved by our medical advisory board