Excessive salivation during sleep, known as nocturnal hypersalivation , is a common phenomenon. While often benign, it can sometimes indicate an underlying disorder. Here is a professional analysis of the main causes and their medical significance.

1️⃣ Sleeping position (on your side or on your stomach)

Sleeping on your side or stomach promotes the natural flow of saliva out of the mouth due to gravity.
👉 The most common cause and generally harmless.