Published on: 6/26/2025
What criteria are used to diagnose narcolepsy?
To diagnose narcolepsy, a healthcare provider usually starts by asking you questions about your health, including questions about your sleep and sleepiness. The healthcare provider also will perform a physical examination of your body. After considering your answers to questions and your physical examination results, the healthcare provider might order some testing. One common approach often used for narcolepsy is a combination of tests. The first test is called polysomnography (PSG), which is an overnight test in a specialized test facility. The morning after the PSG, there is a second test called the Multiple Sleep Latency Test (MSLT), which measures how quickly a person falls asleep in a quiet environment during the day.
Explanation
Narcolepsy is a sleep disorder that makes people very sleepy during the day and can also cause other symptoms. Diagnosing narcolepsy involves several steps and multiple criteria.
Examples of Criteria Used by Healthcare Providers to Diagnosis Narcolepsy:
Medical History and Physical Exam: The healthcare provider will ask questions about your level of daytime sleepiness, sleep patterns, any unusual sleep experiences, and whether you experience episodes of sudden muscle weakness. The healthcare provider may also ask other questions to assess whether another health condition (besides narcolepsy) could be the cause of your symptoms. Asking these medical questions is also known as taking a medical history. In addition to taking a medical history, the healthcare provider will perform a physical examination of your body.
Polysomnography (PSG): This overnight sleep study (in a healthcare facility specializing in PSG) records brain waves, oxygen levels, heart rate, breathing, and body movements while you sleep. The PSG helps identify abnormalities in sleep patterns. More information about the PSG is available at https://sleepeducation.org/what-to-expect-at-your-sleep-study/.
Multiple Sleep Latency Test (MSLT): Conducted the morning after the PSG (and in the same facility as the PSG), the MSLT measures how quickly you fall asleep in a quiet environment during the day. During the MSLT, a patient takes several naps during the day (usually about five naps). The MSLT measures how quickly the patient fall asleep during these naps. Falling asleep very quickly and entering REM sleep rapidly can indicate narcolepsy.
Remember, tests like the PSG and MSLT are just one part of the process. Healthcare providers may also recommend other medical tests, because other health conditions (besides narcolepsy) can also cause a person to feel very sleepy during the day. A healthcare provider will provide personalized medical advice and recommendations. More information about narcolepsy is available at https://sleepeducation.org/sleep-disorders/narcolepsy/.
(References)
- Bassetti CLA, Adamantidis A, Burdakov D, Han F, Gay S, Kallweit U, et al. (2019). Narcolepsy - clinical spectrum, aetiopathophysiology, .... Nature reviews. Neurology, 31324898.
- Ahmed I, & Thorpy M. (2010). Clinical features, diagnosis and treatment of narcolepsy. Clinics in chest medicine, 20488294.
- Ruoff C, & Rye D. (2016). The ICSD-3 and DSM-5 guidelines for diagnosing narcolepsy. Current medical research and opinion, 27359185.
Tell your friends about us.
We would love to help them too.
For First Time Users
What is Ubie’s Doctor’s Note?
We provide a database of explanations from real doctors on a range of medical topics. Get started by exploring our library of questions and topics you want to learn more about.
Learn more about diseases
Was this page helpful?
Purpose and positioning of servicesUbie Doctor's Note is a service for informational purposes. The provision of information by physicians, medical professionals, etc. is not a medical treatment. If medical treatment is required, please consult your doctor or medical institution. We strive to provide reliable and accurate information, but we do not guarantee the completeness of the content. If you find any errors in the information, please contact us.