sleep latency
Also written as: SOL — sleep onset latency
Time required to transition from full wakefulness to sleep onset, measured from lights out to the first epoch of sleep.
Full Definition
Sleep latency, also called sleep onset latency, is the duration of time between turning off the lights (or attempting to sleep) and the first epoch of any stage of sleep as determined by polysomnography. Normal sleep latency in healthy adults is typically 10-20 minutes, though this can vary with age and individual differences. Prolonged sleep latency (>30 minutes) may indicate sleep initiation insomnia, anxiety, or poor sleep hygiene. Very short sleep latency (<5 minutes) can suggest sleep deprivation or excessive sleepiness. Sleep latency is an important parameter in both clinical sleep studies and research protocols.
Usage
Usage note: Can be abbreviated as SOL. Distinguish from REM latency, which measures time to first REM episode.
In Context
- "The patient's sleep latency of 45 minutes indicated significant difficulty with sleep initiation." — Sleep study report
- "Treatment with cognitive behavioral therapy reduced average sleep latency from 60 to 15 minutes." — Insomnia treatment outcome