Waking up to a wet pillow every now and then is usually nothing to worry about.
But if you frequently drool while sleeping, it may be your body’s way of telling you that something deserves attention.
In many cases, nighttime drooling is harmless. In others, it can be linked to an underlying health condition.

1. Your Sleeping Position
One of the most common reasons for drooling is simply sleeping on your side or stomach.
Gravity makes it easier for saliva to escape from your mouth while you sleep, especially if your lips don’t stay fully closed.
2. Nasal Congestion
When your nose is blocked because of a cold, allergies, or sinus problems, you’re more likely to breathe through your mouth.
This can increase the chance of drooling during the night.
If your drooling started around the same time as nasal congestion, treating the underlying cause may help.