MSLT Sleep Study

Also known as: multiple sleep latency test, daytime nap study.

What is a MSLT sleep study?

The MSLT sleep study is a test to measure how quickly you fall asleep at various intervals throughout the day. The test is used for diagnosing problems such as idiopathic hypersomnia or narcolepsy.

What happens during the test?

The patient lies on a bed in a dark room and tries to go to sleep. The patient is allowed to sleep for 15 minutes, or the test ends if the patient does not fall asleep after 20 minutes. The test is repeated 5 times throughout the day, with two hour breaks in between each test.

Is any special preparation needed?

No special preparation is needed for the test. In fact, patients are encouraged to follow their ordinary routine in order to get the most accurate results from the MSLT sleep study.

What are the risk factors?

There are no risk factors related to the MSLT sleep study.

Reviewed by: Mercedes Bello, MD

This page was last updated on: September 16, 2025 12:49 PM