Sleep latency
DEEinschlaflatenz
Sleep latency is how long it takes you to fall asleep, from lights-out to the first moment of sleep. It is usually measured in minutes during a sleep study (polysomnography). A latency of about 10 to 20 minutes is considered healthy. A very short latency (under roughly 5 to 8 minutes) can signal sleep deprivation or excessive daytime sleepiness. A persistently long one points to insomnia or a circadian misalignment. It is a core metric in sleep studies and in the consumer sleep trackers used in longevity contexts.
Last reviewed:
This definition is educational and is not medical advice, a diagnosis, or treatment. Talk to a doctor about any health decisions. Read our full medical disclaimer