Multiple Sleep Latency Test (MSLT)« Back to Glossary Index
The Multiple Sleep Latency Test (MSLT) measures how quickly you fall asleep in a quiet environment during the day. The MSLT typically consists of five scheduled naps, each nap opportunity lasting 20 minutes, separated by two-hour breaks. During each of the nap opportunities, you lie in bed in a darkened, quiet room and try to go to sleep. The time that it takes you to fall asleep is called the sleep latency. You will be allowed to sleep for a maximum of 15 minutes during each opportunity. (You will be awakened if you don’t wake up on your own). If you do not fall asleep within 20 minutes, the nap trial will end.