Sleep Apnea: Symptoms, Causes & Treatment | The Causes Of Sleep Apnea
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Snoring, headaches, extreme fatigue and difficulty concentrating can be signs of sleep apnea.

But what is this pathology? What are its causes and complications? How to get tested?

Discover all this information in this sheet.

Sleep apnea, what is it?

Sleep apnea is manifested by involuntary cessations of breathing, “apneas”, occurring during sleep. Sleep apnea usually occurs in people who are overweight, elderly, or who snore heavily.

These breathing pauses last more than 10 seconds (and can reach more than 30 seconds). They occur several times a night, with varying frequencies. Doctors consider them problematic when there are more than 5 per hour. In severe cases, they occur more than 30 times per hour.

These apneas disturb sleep and mainly result in fatigue on waking, headaches, or drowsiness during the day.

While the majority of people with sleep apnea snore loudly, snoring should not be confused with apnea. Snoring is not considered a health problem in itself and is only rarely accompanied by pauses in breathing. 

Researchers estimate that 30% to 45% of adults are regular snorers. Consult our Snoring sheet to find out more.

Causes of sleep apnea

In the majority of cases, apneas are due to a relaxation of the tongue and throat muscles, which are not toned enough and block the passage of air during breathing. Thus, the person tries to breathe, but the air does not circulate due to the obstruction of the airways. 

This is why doctors speak of obstructive apnea, or obstructive sleep apnea syndrome (OSAS). This excessive relaxation mainly concerns the elderly, whose muscles are less toned. Obese people are also more prone to sleep apnea because excess neck fat decreases the caliber of the airways.

More rarely, apneas are due to a malfunction of the brain, which ceases to send the “order” to breathe to the respiratory muscles. In this case, unlike obstructive apnea, the person does not make a respiratory effort. 

This is called central sleep apnea. This type of apnea occurs especially in people with a serious condition, such as heart disease (heart failure) or neurological disease (for example, meningitis, Parkinson’s disease, etc.). They can also appear after a stroke or in cases of severe obesity. The use of sleeping pills, narcotics, or alcohol is also a risk factor.

Many people have “mixed” sleep apnea, with alternating obstructive and central apneas.

Prevalence of sleep apnea

The frequency of sleep apnea is very high: it is comparable to that of other chronic diseases such as asthma or type 2 diabetes. Sleep apnea can affect adults and children, but its frequency is increasing strongly with age.

It is 2 to 4 times more common in men than in women before the age of 60. After this age, the frequency is the same in both sexes6.

The prevalence estimate varies according to the degree of severity taken into account (number of apneas per hour, measured by the apnea-hypopnea index or AHI). 

Some studies conducted in North America estimate the frequency of obstructive sleep apnea (more than 5 apneas per hour) at 24% in men and 9% in women. About 9% of men and 4% of women have a moderate to severe form of obstructive sleep apnea syndrome.

Possible complications of sleep apnea

In the short term, sleep apnea causes fatigue, headaches, and irritability… It can also bother the spouse because it is often accompanied by loud snoring.

In the long term, if left untreated, sleep apnea has many health consequences:

Cardiovascular illnesses

Sleep apnea significantly increases the risk of cardiovascular disease, through mechanisms that are not fully decoded. We know, however, that each breathing pause causes a deficit of oxygenation of the brain (hypoxia), and that each sudden micro-awakening causes an increase in blood pressure and heart rate.

In the long term, apneas are associated with an increased risk of cardiovascular problems, such as hypertension, stroke, myocardial infarction (heart attack), heart rhythm disorders (arrhythmia), and heart failure. Finally, in the event of significant apnea, the risk of dying suddenly while sleeping is increased.


Lack of sleep, fatigue, the need to take naps, and drowsiness are associated with sleep apnea. They decrease the quality of life of those affected, who often suffer from depression and isolation. A recent study even showed a link between sleep apnea and cognitive disorders in older women.


Lack of sleep induced by apnea increases the risk of accidents, in particular accidents at work and on the road. People with obstructive sleep apnea syndrome are 2 to 7 times more likely to be victims of a traffic accident.

Complications in case of surgery

Sleep apnea, especially if not yet diagnosed, can be a risk factor in general anesthesia. Indeed, anesthetics can accentuate the relaxation of the muscles of the throat and therefore aggravate the apneas. 

Pain medications given after surgery can also increase the risk of severe apneas. It is therefore important to inform your surgeon if you suffer from sleep apnea.

When to consult for sleep apnea?

Doctors believe that the vast majority of people with sleep apnea don’t know it. Most often, it is the spouse who notices the presence of apnea and snoring. It is advisable to consult a doctor if:

  • your snoring is loud and disturbs your partner’s sleep;
  • you often wake up at night having the impression of having trouble breathing or you go to the toilet several times a night;
  • your spouse notices breathing stops while you sleep;
  • you feel tired in the morning and frequently fall asleep during the day. The Epworth sleepiness test measures the degree of sleepiness during the day.

Your doctor can refer you to a center that specializes in sleep studies. In this case, an examination called polysomnography will be carried out. This examination makes it possible to study the different phases of sleep and to measure several parameters to detect sleep apnea and assess its severity. 

In practice, you have to spend a night in the hospital or in a specialized center. Electrodes are placed in different places on the body in order to observe parameters such as brain or muscle activity, the level of oxygen in the blood (to ensure that respiration is efficient), and the different phases of sleep. 

This allows you to know if the person is entering a deep sleep phase or if the apneas are preventing it.

In general, people with sleep apnea do not notice that they are having breathing pauses during the night.

But then, how to detect this disease? What are its symptoms?

Learn more in this sheet.

Sleep apnea symptoms

In general, people with sleep apnea do not notice that they are having breathing pauses during the night. However, apneas cause “micro-awakenings” which alter the quality of sleep.

The most common symptoms are therefore those resulting from fragmented and poor-quality sleep:

  • significant fatigue during the day and upon waking;
  • drowsiness and frequent and uncontrolled falling asleep (in front of the television, at work, while driving, etc.);
  • heavy snoring;
  • headaches on waking;
  • irritability, feeling depressed;
  • memory problems;
  • a drop in school results for the children concerned;
  • a feeling of suffocation or suffocation at night.

Do you know which populations are at risk of developing sleep apnea? And what are the risk factors that favor its appearance?

All the answers can be found in this sheet.

People at risk of sleep apnea

Several factors increase the risk of sleep apnea:


It is the main risk factor for obstructive sleep apnea, especially because excess fat in the neck leads to a narrowing of the airways. Obesity increases the risk of sleep apnea by about 7 times.


The frequency of sleep apnea syndrome doubles or triples after the age of 65.


Men are 2 to 3 times more affected than women.

Ethnic origin

African Americans and Asians have a higher risk of sleep apnea 

Certain abnormalities of the airways or jaws

In some people, the airways are too narrow or the tonsils (nodes at the back of the throat) are too large and obstruct the passage of air. 

This is often the case in children suffering from obstructive sleep apnea syndrome. An abnormality of the jaws can also make the passage of air more difficult. These abnormalities may be accompanied by snoring.

Genetic factors

In some families, obstructive sleep apnea syndrome is very common, due to genetic susceptibility. The risk of suffering from sleep apnea is multiplied by 2 to 4 in close relatives of a person with obstructive sleep apnea syndrome.

neck circumference

The larger the neck (more than 43 cm or 17 inches in circumference in men, more than 40 cm or 16 inches in women), the higher the risk of apnea.

Sleep apnea risk factors

nasal obstruction

People who often have stuffy noses, for example, due to allergies, are more prone to sleep apnea.

Alcohol consumption

Alcohol causes relaxation of the throat muscles which increases the frequency and duration of sleep apnea.

Certain medications

Sleeping pills, muscle relaxants, or anxiolytics, aggravate apneas for the same reasons as alcohol.


It increases the risk of obstructive sleep apnea syndrome, probably because it leads to inflammation of the airways. Smokers are 2.5 times more likely to suffer from sleep apnea than non-smokers 

Type 2 diabetes

Type 2 diabetes is associated with a high risk of sleep apnea, for reasons that are still poorly understood, but often linked to obesity. In diabetics, the prevalence of obstructive sleep apnea syndrome can reach 23%.

Obesity being the main risk factor for sleep apnea, maintaining a healthy weight by adopting a balanced diet and practicing regular physical activity is an effective preventive measure.

The fight against diabetes also makes it possible to limit the risk of occurrence of obstructive sleep apnea. Finally, if you have high blood pressure, it is important to take your medications regularly to reduce your overall risk of cardiovascular disease.

Discover in this sheet other measures to prevent sleep apnea.

How to prevent sleep apnea?

Measures to prevent aggravation

If you suffer from sleep apnea, you can improve the quality of your sleep and reduce your symptoms by adopting simple lifestyle measures. These measures can sometimes eliminate apnea in mild cases:

Losing weight

If you are overweight, losing a few pounds is often enough to improve the quality of your sleep. Thus, a 10% weight loss reduces the severity (frequency and duration) of apneas by 26%.

sleep on the side

For anatomical reasons, airway narrowing is greatest when you sleep on your back. Sleeping on your side often reduces sleep apnea. There are special pajamas (with a ball sewn into the back) that prevent the sleeper from rolling over on their back during the night.

Raise the bed

You can raise the head of the bed a few centimeters, to have the neck and torso slightly inclined during the night (for example, by putting wedges under the legs of the bed). This facilitates the opening of the airways and can be effective in cases of mild apnea.

Avoid sleeping pills and alcohol

When you sleep badly, it is tempting to resort to sleeping pills. However, these increase the relaxation of the muscles of the throat and the tongue and have the consequence of aggravating apneas. Similarly, alcohol should be consumed in moderation.

Stop smoking

Tobacco aggravates the apneas by creating inflammation of the airways and relaxation of the muscles that keep these airways open. In addition, tobacco increases the risk of cardiovascular problems. It is therefore essential to quit smoking. Do not hesitate to ask your doctor for help.

Take care of your allergies

Nasal congestion interferes with breathing and worsens snoring and sleep apnea. If you suffer from recurring allergies, discuss with your doctor to find a suitable treatment. Beware, however, of antihistamine drugs, which have a sedative effect and can aggravate apnea. Consult our Allergic rhinitis sheet to find out more.

Measures to prevent complications

Sleep apnea is a potentially serious condition that should be taken seriously. In addition to trying to shed a few pounds if you’re overweight, it’s important to follow your doctor’s directions and wear your breathing mask every night. See the treatments section.

To reduce the risk of cardiovascular complications, also practice regular physical activity and follow your treatments for hypertension or diabetes.

To date, there are no drugs to cure sleep apnea. However, very effective mechanical treatments exist.

These treatments can also be supplemented with non-drug approaches.

Medical treatments for sleep apnea

Therapy with Continuous Positive Airway Pressure (CPAP or CPAP)

It is the treatment of choice for sleep apnea. A device breathes in the air continuously through the nose, thanks to a mask that is worn at night. Several models of devices and masks are available. 

To designate this device, the term CPAP, which comes from the English “Continuous Positive Airway Pressure”, is often used. The insufflated air keeps the airways continuously open, which eliminates apnea.

Although this treatment is extremely effective, it takes time to get used to sleeping with the mask on. It may feel uncomfortable at first, but you have to be patient. The reduction in symptoms is felt after 4 to 6 weeks, provided the mask is worn every night. 

This treatment improves the quality of life, alertness, and memory of those affected, as well as lowers blood pressure in the event of associated hypertension.

According to the Quebec Lung Association, the device and mask cost $1,500 to $2,200 and are not reimbursable by the Quebec Health Insurance Plan. However, the costs related to the treatment are eligible for tax credits for medical expenses.

Mouth apparatus

This is a gutter molded by the dentist that is worn at night, also called a mandibular advancement orthosis. It keeps the lower jaw and the tongue forward (a few millimeters), which facilitates the passage of air. 

These devices are mainly reserved for people with mild or moderate apnea. They are less efficient than the continuous positive airway pressure device but require less adaptation effort.


Although no medication can cure sleep apnea, some treatments can help reduce apnea by treating the cause. Thus, if the apneas are due to allergic rhinitis, nasal corticosteroids can reduce the number of apneas.

Similarly, in patients with gastro-oesophageal reflux which can aggravate apneas, taking an antireflux drug (such as omeprazole) helps to reduce apneas. Finally, if drowsiness is very important during the day despite CPAP treatment, stimulant drugs may possibly be prescribed. Discuss this with your doctor.

Other: surgery

In some cases, when CPAP therapy does not work or is not well tolerated, surgery may be considered.

There are several types of operations intended to reduce snoring and apnea. However, their effectiveness is relatively low and the apneas tend to reappear sometime after the intervention. There is insufficient evidence to recommend these interventions for people with mild to moderate sleep apnea.

Uvulo-palato-pharyngoplasty (UPPP)

This operation consists of removing the uvula and part of the soft palate, which vibrate during snoring, so as to clear the airways and facilitate the passage of air. It is performed under general anesthesia. 

It is effective in reducing snoring but does not prevent the throat from collapsing. It is only effective on apnea in 50% of cases.

Tonsillectomy and adenoidectomy

These interventions consist of surgically removing the tonsils and adenoids, lymph nodes located in the throat. If they are very swollen, which often happens in children, they can obstruct the passage of air and cause apnea. This operation is mainly proposed in cases of obstructive sleep apnea syndrome in children.

Nose and sinus surgery

It is useful if the apneas are linked to an anomaly of the nasal septum or the sinuses which interferes with breathing.


This “radical” operation is reserved for people with very serious apnea and for whom CPAP ventilation is not effective. It is therefore very rarely offered.

It consists of creating an opening in the trachea, below the throat. This “hole” allows air to enter the lungs without passing through the throat during the night. It can be blocked during the day to resume normal breathing.

Surgery for weight loss

When sleep apnea is due to severe obesity, losing weight can act effectively on apnea. Bariatric surgery, reserved for severe obesity, can reduce the severity of apnea7. To find out more, consult our Obesity sheet.

Complementary approaches

Based on our research of the scientific literature, there is no validated complementary approach to treat sleep apnea.

Image Credit: Photo by Ron Lach from

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