sleep onset latency
The amount of time required to transition from full wakefulness to sleep onset.
Full Definition
Sleep onset latency (SOL) is a quantitative measure of the time elapsed between the intention to sleep (lights out or 'bedtime') and the objective onset of sleep as determined by polysomnographic criteria. Normal sleep onset latency typically ranges from 10 to 20 minutes in healthy adults. Prolonged sleep onset latency (greater than 30 minutes) may indicate sleep onset insomnia, anxiety, or poor sleep hygiene, while very short latency (less than 5 minutes) may suggest sleep deprivation or hypersomnia disorders. This parameter is crucial in sleep study interpretation and insomnia assessment.
Usage
Usage note: Distinguish from general 'sleep latency' which may refer to REM latency; specify 'onset' when referring to initial sleep.
In Context
- "The patient's sleep onset latency of 75 minutes confirmed significant sleep initiation difficulties." — Sleep study results
- "Reduced sleep onset latency following treatment indicated improved sleep quality." — Treatment response evaluation