What Causes Snoring

Overview

Snoring is a common sleep-related issue characterised by the noisy sounds produced when air flows past relaxed tissues in the throat during sleep, causing them to vibrate. It is more common than you think, with 33% of people assigned male at birth (AMAB) and 19% of people assigned female at birth (AFAB) reporting habitual snoring, and almost everyone aware of snoring occasionally.¹ While it can appear seemingly benign, snoring can also indicate underlying health issues that might need attention, making it important to understand what might be causing your snoring.

This article explores the causes of snoring, from its anatomical roots to various lifestyle factors, and its impacts on health and relationships. We will also delve into the potential treatment options and prevention strategies.

Mechanism of snoring

Muscles in the upper airway plays an important role in keeping the airway open while we sleep. When these muscles relax, it can lead to snoring as the airflow is obstructed and the tissues in the throat vibrate as a result, causing the sound of snoring.²

The anatomy of the upper airway includes:

• Nasal passages: the first entry point for air during nasal breathing
• Throat (pharynx): where the nasal passages meet the mouth
• Soft palate and uvula: soft tissues at the back of the mouth
• Tonsils and adenoids: located in the throat

Common causes of snoring

There are many factors which commonly cause snoring and do not typically raise any significant health concerns:

• Anatomy: the size and shape of certain structures in the throat and nose (e.g. a large tongue or tonsils) can lead to snoring by constricting or partially blocking the airways.³ For example, having a deviated septum (where the wall between your nostrils is bent to one side) has been shown to increase the likelihood of snoring by obstructing the airflow.⁴ 

• Sleep position: the position in which you sleep can also affect snoring. You are more likely to snore if you sleep on your back (the supine position) because gravity pulls the tissues surrounding your airway downward, making them more likely to collapse to the back of the throat and narrow your airway.
• Obesity and excess body weight: having excess body weight and tissue, especially around the neck area, can compress the airway and make snoring more likely.⁵
• Age-related factors: as we age, muscle tone in the throat can naturally decrease, and tissues in the throat lose their elasticity. This can make snoring more likely or worsen with age.
• Lifestyle factors: various lifestyle and environmental factors can also contribute to snoring. Substances such as alcohol or sedatives which promote muscle relaxation also affect muscles around your airways, with the relaxation of these muscles causing snoring.⁶ Smoking can also lead to snoring by irritating the tissues in the throat and constriction of the airway.⁷
• Genetics: you might be more likely to snore if someone in your family also snores. Although there is no single gene which causes snoring by itself, there is evidence for a link between your genetics and up to three times increased risk of snoring.^8,9 

Medical conditions causing snoring

Although your snoring might be caused by harmless environmental factors or your natural body anatomy, it is important to be aware that certain medical conditions can also cause snoring as a symptom or side effect:

• Obstructive sleep apnea (OSA): OSA is another common sleep-related disorder which is marked by repeated lapses in breath during sleep due to collapse of the airway. Not everyone who snores has OSA, but most people with OSA snore, and it is a commonly undiagnosed condition. OSA itself is associated with adverse health outcomes such as heart disease and high blood pressure but it can be treated. Therefore it is important to consider if OSA is causing your snoring. 

• Central sleep apnea (CSA): CSA is a less common type of sleep apnea which is also characterised by stopping and starting breathing during sleep. This occurs when the brain fails to transmit the proper signals to the muscles responsible for controlling breathing. Importantly, CSA can be a side effect of more serious conditions including heart failure and stroke. 
• Allergies and colds: allergies or colds commonly cause nasal congestion or inflammation of the airway. This can cause snoring by reducing the flow of air through the airway. 
• Hypothyroidism: an underactive thyroid (hypothyroidism) can affect metabolic function to reduce muscle tone of the airway muscles and therefore cause snoring. Patients with hypothyroidism typically have an enlarged thyroid (a gland found in your neck) which can additionally cause snoring by obstructing your airways.
• Medications: certain medications such as muscle relaxants or antidepressants can also cause snoring by relaxing the muscles surrounding your airway. 

Is snoring dangerous?

The impact snoring can have on a person depends on its type, severity and frequency.

• Light snoring: light or infrequent snoring is normal and does not typically require treatment or prevention.
• Primary snoring: primary, or non-apnoeic, snoring is characterised by snoring that occurs more than 3 times a week. This type of snoring can be significantly more disruptive to those sleeping around you, potentially requiring prevention measures to mitigate its social impact on your relationships. However, it is generally not considered to be a major health concern.¹⁰
• Snoring related to sleep apnea: snoring caused by sleep apnea is considered more dangerous and can have serious long-term complications if the apnea remains untreated. It is important to seek medical assistance if you believe you have symptoms of sleep apnea.

Prevention and treatment

Lifestyle Modifications

Some general measures are suggested to prevent or reduce the likelihood of snoring as the first line of treatment for light or primary snoring.

• Sleep position: sleeping on your side (the lateral position) has been shown to reduce the intensity and frequency of snoring.¹¹ This advice has been demonstrated effective for years: during WW1, soldiers were advised to wear their full rucksacks while sleeping to reduce the risk of snoring and alerting the enemy, as this prevented them from rolling onto their backs in the night.¹²
• Weight management: maintaining a healthy weight can reduce the risk of snoring by decreasing neck circumference and even tongue size to increase airflow.¹³ 
• Avoid triggers: Avoiding triggers such as alcohol, smoking, or allergies causing nasal congestion for several hours before bedtime can reduce the chance of snoring.⁵

Exercises

Oropharyngeal exercises (or myofunctional therapy) are mouth and throat exercises which can help to tone the muscles around the airway and reduce snoring caused by weak muscles (e.g. in ageing). Studies have shown that participants who regularly do these exercises show reduced snoring intensity and frequency.¹⁴ This can help to prevent snoring in the long term without becoming reliant on medical appliances to stop snoring.

Oral appliances

If your natural anatomy causes your snoring, some oral appliances can be used to help prevent snoring:

• Mandibular advancement devices: these devices move the tongue forward to prevent snoring by increasing the airway diameter. This is aimed at snorers where snoring is caused by your tongue partially blocking the back of your throat.
• Tongue-retaining devices: this uses suction to pull the tongue forward during sleep, freeing the airway and preventing snoring.¹⁵
• Tongue muscle electrical stimulation: this treatment is used during the daytime to electrically stimulate and strengthen the muscles in the tongue so that your tongue doesn’t collapse and obstruct your airway when you sleep.¹⁶

Importantly, these devices should always be fitted by specialist dentists. Some patients also report minor side effects of using these devices, such as discomfort, dental misalignment, and excessive salivation.¹⁷

Continuous positive airway pressure (CPAP) therapy

CPAP devices are small masks covering the nose or mouth that can maintain constant positive pressure in the upper airway and prevent the narrowing or collapse of the upper airway during sleep. This treatment is very effective for OSA, but can also be useful for snoring caused by other factors. However, many people report difficulty tolerating the CPAP devices, with side effects including a blocked nose, pressure sores, rashes, and even claustrophobia.¹⁸

Surgical interventions

As a last resort, corrective surgery can be used to treat snoring that isn’t prevented using other treatments. The most common surgical procedures offered for snoring include:

• Uvulopalatopharyngoplasty (UPPP): this procedure usually involves remodelling the uvula, soft palate, and pharyngeal walls to increase the size of the airway and reducing snoring - think of it as a facelift for your throat. However, this is an inpatient procedure which requires general anaesthesia and is often complicated by severe postoperative pain.¹⁹
• Laser-assisted uvulopalatoplasty (LAUP): this is generally considered a less invasive and safer procedure than a UPPP which involves using a laser to reshape the soft palate and uvula. A LAUP can be repeated multiple times to achieve optimal results.
• Palatal stiffening (CAPSO): here, the soft palate is burnt using electrical cautery to cause it to stiffen and reduce the vibrations typically causing snoring. 
• Radiofrequency ablation (Somnoplasty): the inner tissue of the mouth is heated up using thermal energy to help shrink the tissue of the soft palate. This is a minimally invasive procedure that has fewer complications associated with it compared to the other procedures but is a relatively new procedure.²⁰

However, it is important to note that these surgical options do not always work and are not normally permanent solutions - regular snoring usually returns within a few months to a couple of years.

Summary

In summary, snoring is a widespread issue with various underlying causes. While it is mostly benign, it's important to recognise that snoring can be a sign of health problems that need attention. Understanding its causes and taking proactive steps to address them is vital not only for your well-being but also for the quality of sleep and life of those around you. By considering prevention and seeking appropriate treatment, you can significantly improve your sleep and overall health.