Snoring is often regarded as an inconvenience and snorers are the butt of many jokes, but it can have serious health consequences. Most of the health consequences of the more serious condition of Obstructive Sleep Apnoea (OSA) can also occur in regular heavy snoring. There is a slippery slope which leads from pure snoring to obstructive sleep apnoea as things worsen.
Heavy snorers become fearful of going to sleep in public places such as trains or aircraft, and even hotels become a place of dread when the occupants of the room next door bang on the walls or the partner is sleeping in the bathroom!
Snoring occurs when the back of the throat (the airway) narrows during sleep due to relaxation of the muscles which hold it open. This causes the airflow through the throat to accelerate through the narrow portion with a reduction in the air pressure which sucks on the tissues of the throat and causes noisy vibration. The wider open the throat the quieter the flow of air. You can understand this by thinking of a river – a wide river like the River Thames makes no noise at all although millions of gallons of water flow down it every day (over one billion in fact!). If the river was channelled into a narrow gorge it would make a terrible racket, and this is exactly what happens in the narrowed throat.
The narrowed throat also causes increased work for the muscles of breathing and can reduce the volume of air and amount of oxygen reaching the lungs (hypopnoea). This increase in the effort required to breath causes the disturbance to sleep. If you stop breathing altogether (Obstructive Sleep Apnoea (OSA), you will usually wake up with a start and a snorty breath (watch the person opposite you asleep on the train and you will often see this happen). At night the brain is stimulated by messages about the poor breathing, and this disrupts sleep causing lack of morning refreshment and daytime sleepiness.
There are two distinct sounds of snoring: palatal and base of tongue snoring. Whilst some snorers produce one or other of these sounds, there is often a progression leading to both sounds at once as things worsen. It is important to know which type of snoring is occurring because the treatments are different for each.
This type of snoring is caused by vibration of the soft palate which produces a low frequency flutter. This can be very loud and disturbs sleeping partners and others in the vicinity, but never disturbs the snorer, who blanks the noise out from their own sleep.
To hear the sound of nasopalatal snoring listen to the clip below. Note that there is some laboured breathing with increased effort, and this may cause the snorer to rouse from sleep.
Mixed Palatal and Base of Tongue Snoring
When the snoring comes from behind the tongue, the noise is different and has the character of deep breathing giving ‘hissing’ or a ‘white noise’. This is more likely to cause a degree of obstruction to the breathing, and will disturb sleep quality and cause lack of refreshment in the morning. It often accompanies palatal snoring. In the clip below listen for two sounds together:
Palatal flutter – low frequency raspy pig like noise
Base of Tongue – heavy breathing behind the fluttering sound
If gaps or silences occur during snoring then OSA is likely. There are often ‘opening clicks’ heard in the airway during the absence of breathing as tiny amounts of air manage to enter the throat.
To hear the sounds of OSA, click on the video below. Often OSA leads to complete awakeing from obstructed breathing.