Sleep drooling is common and often harmless: people swallow less at night, and an open mouth can let saliva escape. Frequent or excessive drooling may accompany swallowing or breathing problems, but alone it is not a reliable sign of sleep apnea.
Side or stomach sleeping can make saliva more likely to escape; congestion, allergies or infections may also prompt mouth-breathing during sleep. Excessive drooling, called sialorrhea, can involve difficulty controlling saliva or swallowing and may be associated with neurological conditions, medications, reflux, dental issues or pregnancy. Drooling alone does not confirm a medical condition.
Modeling estimates that about 83.7 million U.S. adults may have obstructive sleep apnea, whose common signs include loud snoring, gasping or choking during sleep, nighttime awakenings and daytime sleepiness. There is no clear line between normal nighttime drooling and drooling that may need medical attention, and information on typical amounts among healthy adults is limited.
