Why Do Some People Snore and Others Don’t?

by Dr. Kenny Pang
Snoring has much to do with anatomy.

Your dad snores, your mum snores, your brother snores, and your partner grumpily told you this morning that you do, too. Could snoring be genetic?

Snoring is the sound made by the vibration of soft tissue structures – oropharynx, soft palate, uvula, tonsils, tongue, epiglottis and pharyngeal walls – in the oral cavity. To understand why some people snore and not others, it helps to understand how snoring happens.

But first, one may ask: why do humans snore, at all? 

Compared to other mammals, humans have a much shorter cranio-facial section of the airway in the skull, a bigger cranium (to house the brain), and a longer neck, within which most of the airway is situated. The airway in the neck of a human being is unprotected by the cranio-facial skeleton, and is instead surrounded by skin, muscles and soft tissues. The airway is hence more vulnerable – and prone to collapse, injury and trauma. This is why there is a much higher incidence of snoring and the sleep disorder, obstructive sleep apnea (also spelt as apnoea), in humans as compared to animals. (A Google search will tell you that mammals like English bulldogs have sleep apnea too.) 

Now let’s take a closer look at the human airway, since snoring essentially implies an increased resistance to the inflow of air at the upper airways during breathing. 

The nose warms the air we inhale, and filters dust particles from it. The nose is pivotal in breathing. Any swelling or obstruction in the nose would result in irregular airflow and difficulty breathing. More negative pressure is required to draw air into the lungs, which then leads to yet more negative pressure in the throat (creating a vacuum), and eventually this causes the collapse of the throat muscles and structures.    

The throat in the airway consists of the palate (soft tissue structure containing mainly muscles), the side walls of the throat (mainly muscles and fat), the left and right tonsils (mainly lymphoid tissue), and the tongue. The throat is a dynamic structure that acts as a soft air conduit, to channel air from the external environment into the lungs. Any enlarged or swollen structure/s in this air conduit would narrow the space and result in an obstruction in the breathing passage. As explained earlier, any form of negative pressure or vacuum in the throat would “suck” the structures inward and result in airway obstruction. 

Irregular airflow in this soft air conduit causes vibration – and snoring. 

Differences among people

Given that we are all built differently, the size and patency (the ability to breathe, with airflow passing to and from the respiratory system through the oral and nasal passages) of the upper airway varies from person to person. 

However, of interest, studies have shown that members of the same family tend to have similar anatomical structures and are predisposed to similar illnesses. Hence, as allergies run in families, if one’s parents have allergies or sinus issues, it is likely that the child would face the same predicament; and if the parents snore, chances are, their children might snore too. 

People with nose congestion and/or adeno-tonsillar hypertrophy (enlarged tonsils) have a crowded upper airway, while obese people tend to have a thick and fatty soft palate, which also reduces the space for airflow. People with a small jaw also have less air space available. All these increase the likelihood of airway compromise and laboured breathing. 

This problem becomes especially pronounced during sleep when a person’s muscles are completely relaxed and flaccid (soft). The increased upper airway resistance can result in the collapse and closure of the throat (upper airway obstruction). When this happens, a person may experience breathing stoppages during sleep. This sleep disorder is medically known as Obstructive Sleep Apnea (OSA)

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