What tests are available to diagnose excessive daytime sleepiness?

Reviewed by Yoshinori Abe, MD

Internal Medicine

Excessive daytime sleepiness is diagnosed using a combination of tools. Common tests include validated questionnaires, such as the Epworth Sleepiness Scale, which measure how likely a person is to doze off during everyday activities. In addition, sleep studies performed at specialized healthcare facilities—like polysomnography or the Multiple Sleep Latency Test (MSLT)—help clinicians objectively evaluate sleep patterns and daytime alertness.

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Reviewed for medical accuracy: 07/14/2026

Important Next Steps

Discover causes of your daytime sleepiness See if sleepiness needs urgent care Understand why you're excessively sleepy Find OTC options for daytime sleepiness Find a sleep specialist near you Learn medically valid home remedies for sleepiness Check possible causes of excessive daytime sleepiness

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Explanation

Multiple tests are available for healthcare providers to use to assess excessive daytime sleepiness. These tests are designed to measure how sleepy a person feels or how quickly they fall asleep during the day.

Questionnaires: One example of a questionnaire is called the Epworth Sleepiness Scale (ESS). The ESS asks individuals to rate their likelihood of dozing off in various situations. Questionnaires rely on the person's own perception of their sleepiness.
Testing Performed In A Specialized Healthcare Facility: One example of this kind of test is called the Multiple Sleep Latency Test (MSLT). The MSLT measures how quickly a person falls asleep in a quiet environment during the day. Before scheduling specialized testing, you can get initial insights about your symptoms using a free AI-powered symptom checker at https://ubiehealth.com/symptom-checker.

Test results are only part of the information that a healthcare provider considers when diagnosing excessive daytime sleepiness. Other parts of a medical evaluation include additional questions the healthcare provider may ask you, as well as a physical examination performed by the healthcare provider. Using this information all together can give the healthcare provider more comprehensive understanding of a person's daytime sleepiness.

(References)

Taillard J, Micoulaud-Franchi JA, Martin VP, Peter-Derex L, & Vecchierini MF. (2024). Objective evaluation of excessive daytime sleepiness. Neurophysiologie clinique = Clinical neurophysiology, 38401239.
Fong SY, Ho CK, & Wing YK. (2005). Comparing MSLT and ESS in the measurement of .... Journal of psychosomatic research, 15771871.
Johns MW. (2000). Sensitivity and specificity of the multiple sleep latency test .... Journal of sleep research, 10733683.

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