Snoring is caused by the vibration of tissues lining the upper air passages. Snoring in most people is due to multiple factors, each playing some part in the snoring process.
Relaxation of muscles causes the walls of the upper airway to fall together and narrow, causing them to vibrate. The tongue may fall back into the throat when sleeping on the back and contribute to snoring.
Nasal blockages due to conditions such as nasal allergies or deformities of the nasal septum (the cartilage partition between the two sides of the nose) can cause poor nasal airflow and mouth breathing, making the situation worse.
A deviated nasal septum, turbinate hypertrophy, large adenoids and tonsils, nasal polyps, long soft palate and a bulky tongue can narrow the airway.
Other factors which can influence the snoring condition are: