Drooling during sleep is a common phenomenon that occurs in many people. Although in most cases it is completely normal, in some cases it may be related to certain health problems or sleep habits. Below, we’ll explore the most common causes and when it might be a sign of something more serious.

During deep sleep, especially during REM sleep, the body’s muscles relax, including those of the mouth and jaw. This can cause the mouth to open slightly and saliva to flow out instead of being swallowed as it does when we are awake.

Sleeping on your stomach or side makes it easier for gravity to release saliva. On the other hand, those who sleep on their backs tend to swallow saliva more easily, reducing drooling.

When your nose is stuffy due to allergies, colds, or sinusitis, you breathe more through your mouth, causing saliva to flow uncontrollably.