How to Test for Narcolepsy

How to Test for Narcolepsy

Narcolepsy is a chronic neurological disorder where the main symptom is EDS—excessive daytime sleepiness as well as sudden sleep attacks. It is a lifelong sleep disorder (hence the chronic etiquette) that can be managed and held under control with the proper medical help. Even though narcolepsy is a rare condition, it’s estimated that less than 100 people are affected from 100.000. 

Precisely because it’s an uncommon sleep disorder, narcolepsy is often misdiagnosed, undiagnosed, or diagnosed late, after a lot of the symptoms have already started. And of course, for anything health-related, the earlier you get diagnosed, the better, as an early diagnosis of narcolepsy can significantly increase the quality of life for patients. 

Diagnosing Narcolepsy

Narcolepsy diagnosis is a process. In any event, it can be done by a primary care doctor, who can refer you to a specialist in the field of sleep disorders (a neurologist, a sleep specialist, and sometimes a psychiatrist). Once the narcolepsy diagnosis starts, you will probably need to go to a sleep clinic and do a sleep study as well as a set of sleep tests.

PSG and MSLT Tests

When a doctor thinks that you may suffer from narcolepsy or a different sleep disorder, then they usually prescribe two specific sleep studies.

Polysomnography (PSG)

This sleep study is designed to track your breathing pattern, your muscle movement, eye movement as well as brain activity. It's a test performed in a sleep clinic in which you'll have to stay the night.

PSG looks at the stages of your sleep and your awakenings, and it's also used to diagnose sleep apnea.

The Multiple Sleep Latency Test (MSLT)

This sleep study is usually done in the morning, right after the PSG one. While you're doing the MSLT, you will also stay connected to the PSG sensors. There are five different intervals at which you will be told to fall asleep, and the MSLT test will look at how much time you need to fall asleep and how much time you need to enter the REM (rapid eye movement) sleep phase.

Common Questions Asked in Narcolepsy Diagnosis

One of the key steps in diagnosing narcolepsy is answering a set of questions that the sleep specialist will ask you. They will try to induce more information about your symptoms, your sleep patterns, as well as your health history. These questions usually are:

  • How many hours do you sleep, on average, every night?
  • Is it hard for you to fall asleep at night?
  • Do you wake several times in the middle of sleep?
  • Do you feel sleepy in the daytime and often take naps?
  • Do you experience daytime sleepiness and daytime drowsiness?
  • Do you fall asleep suddenly in the middle of the day?
  • Does this affect your performance at work or school, or when performing daily tasks like driving or operating machinery?
  • In the past two weeks, how many times have you fallen asleep without wanting to?
  • Do you feel fresh and energized when you wake up in the morning or from a nap?
  • Do you dream when you're napping?
  • Does your sleep pattern change during the weekend? Do you sleep more on Saturdays and Sundays than during the workweek?
  • Do you experience hallucinations or temporary paralysis when you fall asleep or wake up?
  • Do you snore (and how loud), and do you make choking sounds while you're sleeping? Do you suffer from sleep apnea?
  • Have you ever experienced cataplexy, which is a brief and sudden loss of muscle tone?

By answering these questions, you'll make it easier for your doctor to find out whether you're suffering from obstructive sleep apnea and whether you have any other sleep disorders or neurological disorders.

Other Parts of the Diagnosis Process

In order to find out more information about your sleep patterns and sleep habits, the sleep specialist may ask you to do an ESS test which is a measure for the Epworth Sleepiness Scale. ESS measures how much excessive sleepiness you're currently experiencing and is used to determine whether it should be somehow treated or whether it's a symptom of a more serious condition, like narcolepsy.

You may also need to keep a sleep log, which is basically a sleep diary where you fill in the details of your sleep habits.


These are some of the commonly used methods to diagnose narcolepsy, but they aren't the only ones. It's important to remember that if you think you have narcolepsy, you should talk to a medical professional as soon as possible to get proper treatment early on and improve your quality of life.