When you fall asleep, the muscles in your throat, tongue, and the roof of your mouth (soft palate) relax. If they relax too much, they can partially block your airway. Several factors can contribute to this: Snoring - Diagnosis and treatment - Mayo Clinic
Snoring is a common condition that occurs when air cannot flow freely through the nose and throat while you sleep. This restricted airflow causes the surrounding tissues to vibrate, producing the characteristic rattling or harsh sound. Why Snoring Happens SNORING