Why Do We Snore?
In the living world, only Homo sapiens (humans) snore as a result of their natural development. Some animals make loud breathing sounds, particularly when asleep, but this is because of characteristics bred into them, like the British bulldog or an overweight family dog.
Snoring is not a good characteristic in terms of survival in the wild as it can alert a predator to the presence of an easy, sleeping target.
Humans snore mainly because of speech and posture. The evolution of speech meant that a number of changes had to happen to the throat, so that the rudimentary grunts and noises of our chimpanzee ancestors could become the wide range complex framework of interaction we call speech.
Firstly, the breathing tube had to become longer because the larynx (voice box), where coarse sound is produced, had to be separated from the mouth, where sound is made into speech. This separation is called the throat, or in medical terms, the oropharynx. As a result the throat is a muscular tube that can collapse at night as it is not held open by bone or cartilage, unlike the mouth or larynx.
Secondly, for range of speech the tongue needed to change its relationship within the mouth, sitting further back. This caused narrowing of the gap between the tongue and the back of the throat² which when combined with a marginal collapse of the throat, triggers turbulent airflow and snoring.
Much like speech, the evolution of posture caused changes that trigger snoring.
The most notable change was walking on two feet. The upright nature of this meant that the relationship of the skull and the throat altered, with the throat being located more centrally under the skull, rather than being further forward. This narrowed any available throat space, as it was confined against the hard tissue of the spine. Narrowing of this area again made blockage easier to occur, especially at night when muscle tone was lost in sleep.
We have a built-in predilection to snore due to our development of speech and upright posture. Yet not all of us snore.
Why are some people different to others?
Firstly, it may simply be due to the shape of one’s face, skull and neck. There are certain features that people are born with, which make them more susceptible to snoring. These include a significant lower jaw underbite, a small mouth, a large tongue, a small lower jaw or a misshapen epiglottis.
Then there are other acquired reasons for snoring, like a blocked nose, large tonsils, long soft palate and cysts or lumps in the throat. Finally, obesity is another cause of snoring simply because the weight of fat in the neck can collapse the airway.