Snoring occurs mainly due to the soft palate at the back roof of mouth which closes the nasal passage while swallowing or uvula; a dangling like thing comes in the way of air. During sleep they get relaxed during night making the passage narrower for the air. So whenever you breathe throat muscle vibrates and when these vibrations are stopped it causes snoring because of blocking. It mainly occurs when a person sleeps on his back.
Another reason for snoring is overweight. Double chin presses on the throat causing obstruction in the air passage. Snoring also happens due to nose related problems like nostril squeezes during the change in the season and we breathe from mouth. Our throat is not familiar for this change and hence we snore.
With change of septum, the small growths between our nostrils change not how the air is drawn inside but how much is drawn.
Sleeping pills are another cause of snoring because they relax the throat muscle. A deep sleep in natural way also has same effects.
It is seen that the snoring is more common in men than the women because women creates a hormone named PROGESTERONE which some experts believe reduce snoring.
Loudness of snoring can be up to 69 decibels.