Anatomy of Snoring and OSA
When you breathe, air travels through passages in your nose and throat. When these air passages are wide enough to let air flow freely, you breathe normally. But if the passages become narrowed, you may snore. And if they become blocked and you can't breathe, you have sleep apnea.
Nasal Structures
The septum is the wall that divides the left half of the nose from the right half. Turbinates are ridges in the nasal passage. The purpose of the structures is to warm, filter and humidify the air entering your lungs.
Throat Structures
Air flows past soft, flexible structures where the mouth meets the throat: the soft palate, uvula, tonsils, and back of the tongue. Throat muscles hold those structures in place. While you sleep, the throat muscles relax a bit but they normally stay tight enough to keep the airway open. See the blue airflow line above.
Snoring
If the structures in your throat are bulky or throat muscles relax too much, the airway may be partly blocked. Air flowing through the throat makes these structures vibrate. That vibration is what causes snoring.
Sleep Apnea
Blockage in the throat can partially or completely stop air from flowing. If this happens, the brain tells the body to wake up just enough to tighten the muscles and open the airway. This cycle may repeat many times during the night.
Problems in the Nose and Jaw
Problems in the structure of the nose may obstruct breathing. A crooked (deviated) septum or swollen turbinates can make snoring worse or lead to apnea. Also, a receding jaw may make the tongue sit too far back, so it is more likely to block the airway when you're asleep.