Snoring is increasingly gaining prominence and there is a growing awareness of the issue. This not just because it can be highly irritating for snorers and their partners – in the vast majority of cases it is actually a medical condition and can lead to further health problems. One in every two men over the age of 40 and one in every seven to eight women of this age snores. Within this group, men snore more loudly and more often than women and are more prone to sleep apnoea. From the age of 65, both genders snore as much and as loudly as each other.
Snoring is caused by turbulent airflow at narrow points of the nose and throat during sleep. The younger a snorer is, the more likely it is that anatomical problems are the cause (nose, adenoids). Restricted nasal breathing plays a major role in around 20% of cases in adult snorers. In such cases, medical ear, nose and throat interventions are the treatment of choice. Narrow points in the nose are usually caused by anatomical constrictions (deviated nasal septum or enlarged nasal turbinates) or – commonly – by swelling due to allergies or infections. In the throat, narrow points are normally "functional" due to tension being relaxed in muscles that are normally permanently tensed (tonic). The main cause in most cases is the thick muscle at the base of the tongue. This falls too far back due to the effect of gravity when you lie down (particularly on your back) and relaxation during sleep, consequently restricting the upper airway or even totally blocking it. During the day, our throat muscles are almost always sufficiently tensed for enough air to flow through the throat and into the lungs as we breathe. When we are asleep, however, almost all of our muscles relax to varying degrees, which means that there is a "functional collapse" of the muscles in the throat. If air can still pass through, it has to squeeze through the narrow gap. The flow of air then becomes turbulent and causes the soft palate and uvula to vibrate. This is called snoring.
Source: Schlafen für Aufgeweckte, Dr. med. Michael Feld, 3. Auflage 2015