Why does snoring occur?
Snoring occurs when a person’s airway volume is reduced and the passing of air through this smaller gap leads to turbulence and vibration of a part of the throat (just behind the tongue), called the pharynx. This movement of the pharynx causes the snoring sound.
Why does this noise not occur when we are awake?
Whilst we are awake, several muscles hold the jaw forwards, which helps to keep the pharynx (upper part of the throat) open.
As we fall asleep these muscles lose their tone (relax), allow the jaw to drop back and reduce the airway (it narrows). This is especially apparent if we lie on our back, where gravity will also pull the jaw down/ backwards.
The smaller the airway to begin with, the narrower it will become during sleep and hence the greater the chance of the pharynx vibrating (causing the snoring noise). The airway can be narrowed by patient anatomy. It is also affected by fat deposits and muscle size and position, so can affect athletes. Notably only 70% of OSA sufferers are overweight, which leaves 30% that are NOT overweight!
There is a lot of clinical evidence (and logic) that support the use of Mandibular Repositioning Devices (MAD’s) / Mandibular Repositioning Appliances (MRA’s). As they simply hold the jaw in a forward position to prevent/ reduce the airway collapse during sleep.
Will Snoring Always Reduce with Treatment?
Interestingly, there have been several cases of obstructive sleep apnoea that, when treated, have led to an increase in snoring. This was because obstructive sleep apnoea is linked to full closure of the airway (intermittent suffocation). So, a reduction in this can be achieved through an increased airway however this increase may allow the pharynx to vibrate (leading to the snoring). It is better to snore a little than suffer the incredibly deleterious effects of obstructive sleep apnoea. In such a case a combined therapy could be considered to help hold the airway open enough.
Risk Factors for Snoring
The chance of an individual snoring is increased by a combination of factors;
- Being overweight (due to more fat around the neck, which can narrow the throat).
- Increased alcohol intake (especially at night, can relax the throat muscles).
- Some medications raise the risk (especially muscle relaxants, sleeping tablets, anaesthetic drugs, oral steroids, and epilepsy drugs).
- Sleeping on the back because when we sleep the tongue loses its muscle tension (patency), can fall back, allowing the lower jaw to move back, which causes the upper airway to partially/ fully close off). Snoring is almost always worse when people sleep on their back.
- Men are at a higher risk than women.
- Being middle aged.
- Sleep apnoea sufferers also tend to snore (but not all those that snore have sleep apnoea).
- Blocked nose/ sinus issues can increase the need for mouth breathing and hence snoring.
- Nasal passages can be narrowed due to patient anatomy (they are born and naturally develop this way).
- Nasal anatomy can also be affected by other factors (nasal polyps, a large tongue or thyroid swellings). Children often suffer with snoring due to enlarged tonsils and adenoids. If they start snoring, perhaps this may be a warning sign that something is changing.
- Snoring is more likely in pregnancy.
Types of Breathing
Functional breathing, considered to be specifically breathing in and out through the nose (not the mouth), is generally believed to be far healthier.
Mouth Breathing (termed non-functional) i.e. not breathing through the nose. Notably, the back of the throat has relatively soft sides, which can vibrate, whereas the nose walls are harder and vibrate less easily.
Is snoring a common problem?
The incidence of snoring is very high, with approximately 40% of men having at least mild snoring occasionally (but not every night). For women, the number is slightly smaller (around 30%). About 15% of people snore on most nights. People of any age can snore. Even some children have a problem with snoring, however middle-aged people are the most likely age group to snore.
How does it affect people?
Snoring is often a big problem for couples and families. In many cases, the snorer ends up sleeping alone in a separate room, sometimes at the other end of the house.
Sleeping in the same room as a chronic snorer can cause a sleeping partner to miss out on the benefits of a good night sleep.
Some people snore so loud that an entire family can be affected in a home (even in different rooms with doors closed).
Smoking can affect those who passively breathe it in and cause medical issues, similarly passive sleep deprivation can reap havoc with our health.
The Anatomy of Snoring
Snorers generally have a narrow airway which can affect their breathing. If this airway continues to narrow (sometimes due to weight gain or other factors) then it can close off completely, causing an Apnoea (a temporary cessation of breathing, especially during sleep). The person essentially begins to suffocate, the person’s feedback nerves (usually) send a stimulatory response to the brain, which wakes the person from their deep sleep into a far shallower sleep and causes them to breathe again. In most cases they do not fully wake into consciousness and so are unaware of the issue other than the worsening symptoms they feel during the day (fatigue, tiredness etc.).
This regularly disturbed night’s sleep has effects which go way beyond the psychological effects of sleep deprivation and includes very serious physiological issues such as daytime tiredness and an inability to focus on work, study (or driving/ control of large machinery!). There are also far reaching medical problems (often termed co-morbidities) associated with sleep deprivation.
Sleep apnoea affects approximately 10% of snorers to a significant degree which is deeply concerning in that there are many medical issues related to it, including;
- High blood pressure
- Heart Attacks
- Developmental defects/ issues in children (such as under-developed jaws)
- Possible links with Attention deficit hyperactivity disorder (ADHD).