What is obstructive sleep apnea

Obstructive sleep apnea (OSA) is a relatively common potentially serious sleep disorder where the muscles of your throat intermittently relax and narrow during sleep, block your airway during sleep and interrupting normal breathing. It causes breathing to repeatedly stop and start during sleep. A noticeable sign of obstructive sleep apnea is snoring. This may lead to regularly interrupted sleep, which can have a big impact on quality of life and increases the risk of developing certain conditions.

There are two types of breathing interruption characteristic of obstructive sleep apnea:

1. Apnea– where the muscles and soft tissues in the throat relax and collapse sufficiently to cause a total blockage of the airway; it’s called an apnea when the airflow is blocked for 10 seconds or more
2. Hypopnea– a partial blockage of the airway that results in an airflow reduction of greater than 50% for 10 seconds or more

People with obstructive sleep apnea may experience repeated episodes of apnea and hypopnea throughout the night. These events may occur around once every one or two minutes in severe cases.

As many people with obstructive sleep apnea experience episodes of both apnea and hypopnea, doctors sometimes refer to the condition as obstructive sleep apnea-hypopnea syndrome (OSAHS).

The term “obstructive” distinguishes obstructive sleep apnea from rarer forms of sleep apnea, such as central sleep apnea, which is caused by the brain not sending signals to the breathing muscles during sleep.

Treatments for obstructive sleep apnea are available. One treatment involves using a device that keep your airway open while you sleep. Another option is a mouthpiece to thrust your jaw forward during sleep. In more severe cases, surgery may be an option too.

In many cases, self-care may be the most appropriate way for you to deal with obstructive sleep apnea. Try these tips:

• Lose weight. If you’re overweight or obese, even a slight loss of excess weight may help relieve constriction of your airway. Losing weight can also improve your health and quality of life, and may reduce your sleepiness during the day.
• Exercise. Exercising, such as aerobic exercise and strength training, can help improve your condition. Aim to exercise about 150 minutes a week, and generally try to exercise most days of the week.
• Avoid alcohol and medications such as tranquilizers and sleeping pills. Alcohol can worsen obstructive sleep apnea and sleepiness and may lead to weight gain. Certain medications also can worsen your sleep.
• Sleep on your side or abdomen rather than on your back. Sleeping on your back can cause your tongue and soft palate to rest against the back of your throat and block your airway. To prevent sleeping on your back, try sewing a tennis ball in the back of your pajama top.
• Keep your nasal passages open while you sleep. If you have congestion, use a saline nasal spray to help keep your nasal passages open. Talk to your doctor about using nasal decongestants or antihistamines, because some medications may only be recommended for short-term use.

Obstructive sleep apnea causes

It’s normal for the muscles and soft tissues in the throat to relax and collapse to some degree while sleeping. For most people this doesn’t cause breathing problems.

Obstructive sleep apnea occurs when the muscles in the back of your throat relax too much to allow normal breathing. These muscles support structures including the soft palate, the uvula — a triangular piece of tissue hanging from the soft palate, the tonsils and the tongue.

When the muscles relax, your airway narrows or closes as you breathe in and breathing may be inadequate for 10 to 20 seconds. This may lower the level of oxygen in your blood and cause a buildup of carbon dioxide.

Your brain senses this impaired breathing and briefly rouses you from sleep so that you can reopen your airway. This awakening is usually so brief that you don’t remember it.

You can awaken with a transient shortness of breath that corrects itself quickly, within one or two deep breaths. You may make a snorting, choking or gasping sound.

This pattern can repeat itself five to 30 times or more each hour, all night long. These disruptions impair your ability to reach the desired deep, restful phases of sleep, and you’ll probably feel sleepy during your waking hours.

People with obstructive sleep apnea may not be aware that their sleep was interrupted. In fact, many people with this type of sleep apnea think they slept well all night.

Risk factors for obstructive sleep apnea

Anyone can develop obstructive sleep apnea. However, certain factors put you at increased risk, including:

• Excess weight. Around half the people with obstructive sleep apnea are overweight. Fat deposits around the upper airway may obstruct breathing. However, not everyone with obstructive sleep apnea is overweight and vice versa. Thin people can develop the disorder, too.
• Narrowed airway. You may inherit naturally narrow airways. Or, your tonsils or adenoids may become enlarged, which can block your airway.
• Having an unusual inner neck structure – such as a narrow airway, large tonsils, adenoids or tongue, or a small lower jaw
• High blood pressure (hypertension). Obstructive sleep apnea is relatively common in people with hypertension.
• Nasal congestion. Obstructive sleep apnea occurs twice as often in those who have consistent nasal congestion at night, regardless of the cause. Obstructive sleep apnea occurs more often in people with deviated septum, where the tissue in the nose that divides the two nostrils is bent to one side, or nasal polyps, which may be a result of the airways being narrowed.
• Smoking. People who smoke are more likely to have obstructive sleep apnea.
• Diabetes. Obstructive sleep apnea may be more common in people with diabetes.
• Being male. In general, men are twice as likely as women to have obstructive sleep apnea. It’s not known why obstructive sleep apnea is more common in men than in women, but it may be related to different patterns of body fat distribution
• A family history of obstructive sleep apnea. If you have family members with obstructive sleep apnea, you may be at increased risk. There may be genes inherited from your parents that can make you more susceptible to obstructive sleep apnea
• Asthma. Recent research has found an association between asthma and the risk of obstructive sleep apnea.
• Being 40 years of age or more – although obstructive sleep apnea can occur at any age, it’s more common in people who are over 40
• Having a large neck – men with a collar size greater than around 43cm (17 inches) have an increased risk of developing obstructive sleep apnea
• Taking medicines with a sedative effect – such as sleeping tablets or tranquillizers
• Alcohol – drinking alcohol, particularly before going to sleep, can make snoring and sleep apnoea worse
• The menopause (in women) – the changes in hormone levels during the menopause may cause the throat muscles to relax more than usual.

Obstructive sleep apnea prevention

It’s not always possible to prevent obstructive sleep apnea, but making certain lifestyle changes may reduce your risk of developing the condition.

These include:

• losing weight if you’re overweight or obese
• limiting how much alcohol you drink and avoiding alcohol in the evening
• stopping smoking if you smoke
• avoiding the use of sleeping tablets and tranquillizers

Obstructive sleep apnea symptoms

The symptoms of obstructive sleep apnea are often first spotted by a partner, friend or family member who notices problems while you sleep.

Signs and symptoms of obstructive sleep apnea include:

• Excessive daytime sleepiness
• Loud snoring
• Noisy and labored breathing
• Repeated short periods where breathing is interrupted by gasping or snorting
• Observed episodes of breathing cessation during sleep
• Abrupt awakenings accompanied by gasping or choking
• Awakening with a dry mouth or sore throat
• Morning headache
• Difficulty concentrating during the day
• Experiencing mood changes, such as depression or irritability
• High blood pressure
• Nighttime sweating
• Decreased libido

Some people with obstructive sleep apnea may also experience night sweats and may wake up frequently during the night to urinate.

During an episode, the lack of oxygen triggers your brain to pull you out of deep sleep – either to a lighter sleep or to wakefulness – so your airway reopens and you can breathe normally.

These repeated sleep interruptions can make you feel very tired during the day. You’ll usually have no memory of your interrupted breathing, so you may be unaware you have a problem.

Obstructive sleep apnea complications

Obstructive sleep apnea is considered a serious medical condition. Complications may include:

• Daytime fatigue and sleepiness. The repeated awakenings associated with obstructive sleep apnea make normal, restorative sleep impossible. People with obstructive sleep apnea often experience severe daytime drowsiness, fatigue and irritability. They may have difficulty concentrating and find themselves falling asleep at work, while watching TV or even when driving. Children and young people with obstructive sleep apnea may do poorly in school and commonly have attention or behavior problems.
• Cardiovascular problems. Sudden drops in blood oxygen levels that occur during obstructive sleep apnea increase blood pressure and strain the cardiovascular system.
  • Many people with obstructive sleep apnea develop high blood pressure (hypertension), which can increase the risk of heart disease.
  • The more severe the obstructive sleep apnea, the greater the risk of coronary artery disease, heart attack, heart failure and stroke. Men with obstructive sleep apnea appear to be at risk of heart failure, while women with obstructive sleep apnea don’t.
  • Obstructive sleep apnea increases the risk of abnormal heart rhythms (arrhythmias). These abnormal rhythms can lower blood oxygen levels.
  • If there’s underlying heart disease, these repeated multiple episodes of low blood oxygen could lead to sudden death from a cardiac event.
• Developing type 2 diabetes – although it’s unclear if this is the result of an underlying cause, such as obesity
• Complications with medications and surgery. Obstructive sleep apnea also is a concern with certain medications and general anesthesia. These medications, such as sedatives, narcotic analgesics and general anesthetics, relax your upper airway and may worsen your obstructive sleep apnea. If you have obstructive sleep apnea, you may experience worse breathing problems after major surgery, especially after being sedated and lying on your back. People with obstructive sleep apnea may be more prone to complications after surgery. Before you have surgery, tell your doctor if you have obstructive sleep apnea or symptoms related to obstructive sleep apnea. If you have obstructive sleep apnea symptoms, your doctor may test you for obstructive sleep apnea prior to surgery.
• Eye problems. Some research has found a connection between obstructive sleep apnea and certain eye conditions, such as glaucoma. Eye complications can usually be treated.
• Sleep-deprived partners. Loud snoring can keep those around you from getting good rest and eventually disrupt your relationships. Some partners may even choose to sleep in another room. Many bed partners of people who snore are sleep deprived as well.

People with obstructive sleep apnea may also complain of memory problems, morning headaches, mood swings or feelings of depression, and a need to urinate frequently at night (nocturia).

Research has shown someone who has been deprived of sleep because of obstructive sleep apnea may be up to 12 times more likely to be involved in a car accident.

If you’re diagnosed with obstructive sleep apnea, it may mean your ability to drive is affected. It’s your legal obligation to inform the department of motor vehicles (DMV) about a medical condition that could have an impact on your driving ability.

Once a diagnosis of obstructive sleep apnea has been made, you may be advised to stop driving until your symptoms are well controlled.

Obstructive sleep apnea diagnosis

Obstructive sleep apnoea can usually be diagnosed after you’ve been observed sleeping at a sleep clinic, or by using a testing device worn overnight at home.

If you think you have obstructive sleep apnea, it’s important to visit your doctor in case you need to be referred to a sleep specialist for further tests and treatment.

To diagnose obstructive sleep apnea, your doctor may make an evaluation based on your signs and symptoms, an examination, and tests. Your doctor may refer you to a sleep specialist in a sleep center for further evaluation.

You’ll have a physical examination, and your doctor will examine the back of your throat, mouth and nose for extra tissue or abnormalities. Your doctor may measure your neck and waist circumference and check your blood pressure.

Before seeing your doctor it may be helpful to ask a partner, friend or relative to observe you while you’re asleep, if possible. If you have obstructive sleep apnea, they may be able to spot episodes of breathlessness.

It may also help to fill out an Epworth Sleepiness Scale questionnaire. This asks how likely you’ll be to doze off in a number of different situations, such as watching TV or sitting in a meeting.

The final score will help your doctor determine whether you may have a sleep disorder.

For example, a score of 16-24 means you’re excessively sleepy and should consider seeking medical attention. A score of eight to nine is considered average during the daytime.

Figure 1. Epworth Sleepiness Scale

A sleep specialist may conduct additional evaluations to diagnose your condition, determine the severity of your condition and plan your treatment. The evaluation may involve overnight monitoring of your breathing and other body functions as you sleep. Tests to detect obstructive sleep apnea include:

• Polysomnography. During this sleep study, you’re hooked up to equipment that monitors your heart, lung and brain activity, breathing patterns, arm and leg movements, and blood oxygen levels while you sleep. You may have a full-night study, in which you’re monitored all night, or a split-night sleep study. In a split-night sleep study, you’ll be monitored during the first half of the night. If you’re diagnosed with obstructive sleep apnea, staff may wake you and give you continuous positive airway pressure for the second half of the night. This test can help your doctor diagnose obstructive sleep apnea and adjust positive airway pressure therapy, if appropriate. This sleep study can also help rule out other sleep disorders, such as periodic limb movements of sleep or narcolepsy, which also can cause excessive daytime sleepiness, but require different treatment.
• Home sleep apnea testing. Under certain circumstances, your doctor may provide you with an at-home version of polysomnography to diagnose obstructive sleep apnea. This test usually involves measurement of airflow, breathing patterns, heart rate and blood oxygen levels, and possibly limb movements and snoring intensity.

Your doctor also may refer you to an ear, nose and throat doctor to rule out any anatomic blockage in your nose or throat.

Determining the severity of obstructive sleep apnea

The severity of obstructive sleep apnea is determined by how often your breathing is affected over the course of an hour. These episodes are measured using the apnea-hypopnea index (AHI).

Severity is measured using the following criteria:

• Mild obstructive sleep apnea – an apnea-hypopnea index reading of 5 to 14 episodes an hour
• Moderate obstructive sleep apnea – an apnea-hypopnea index reading of 15 to 30 episodes an hour
• Severe obstructive sleep apnea – an apnea-hypopnea index reading of more than 30 episodes an hour

Current evidence suggests treatment is most likely to be beneficial in people with moderate or severe obstructive sleep apnea. However, some research has suggested treatment may also help some people with mild obstructive sleep apnea.

Obstructive sleep apnea treatment

Obstructive sleep apnea is a treatable condition, and there are a variety of treatment options that can reduce the symptoms.

Treatment options for obstructive sleep apnea include:

• Lifestyle changes – such as losing excess weight, cutting down on alcohol and sleeping on your side
• Using a continuous positive airway pressure (CPAP) device – these devices prevent your airway closing while you sleep by delivering a continuous supply of compressed air through a mask
• Wearing a mandibular advancement device (MAD) – this gum shield-like device fits around your teeth, holding your jaw and tongue forward to increase the space at the back of your throat while you sleep

Surgery may also be an option if obstructive sleep apnea is thought to be the result of a physical problem that can be corrected surgically, such as an unusual inner neck structure.

However, for most people surgery isn’t appropriate and may only be considered as a last resort if other treatments haven’t helped.

The treatments mentioned above can often help control the symptoms of obstructive sleep apnea, although treatment will need to be lifelong in most cases.

If obstructive sleep apnea is left untreated, it can have a significant impact on your quality of life, causing problems such as poor performance at work and school, and placing a strain on your relationships with others.

Lifestyle changes

For milder cases of obstructive sleep apnea, your doctor may recommend lifestyle changes:

• Lose weight if you’re overweight.
• Exercise regularly.
• Drink alcohol moderately, if at all, and don’t drink several hours before bedtime.
• Quit smoking.
• Use a nasal decongestant or allergy medications.
• Don’t sleep on your back.

If these measures don’t improve your sleep or if your obstructive sleep apnea is moderate to severe, then your doctor may recommend other treatments. Certain devices can help open up a blocked airway. In other cases, surgery may be necessary.

Therapies

Positive airway pressure

If you have obstructive sleep apnea, you may benefit from positive airway pressure. In this treatment, a machine delivers air pressure through a piece that fits into your nose or is placed over your nose and mouth while you sleep.

Positive airway pressure reduces the number of respiratory events that occur as you sleep, reduces daytime sleepiness and improves your quality of life.

The most common type is called continuous positive airway pressure (CPAP). With this treatment, the pressure of the air breathed is continuous, constant and somewhat greater than that of the surrounding air, which is just enough to keep your upper airway passages open. This air pressure prevents obstructive sleep apnea and snoring.

Although CPAP (continuous positive airway pressure) is the most consistently successful and most commonly used method of treating obstructive sleep apnea, some people find the mask cumbersome, uncomfortable or loud. However, newer machines are smaller and less noisy than older machines.

Also, with some practice, most people learn to adjust the mask to obtain a comfortable and secure fit. You may need to try different types to find a suitable mask. Several options are available, such as nasal masks, nasal pillows or face masks.

If you’re having particular difficulties tolerating pressure, some machines have special adaptive pressure functions to improve comfort. You also may benefit from using a humidifier along with your CPAP system.

CPAP may be given at a continuous (fixed) pressure or varied (autotitrating) pressure. In fixed CPAP, the pressure stays constant. In autotitrating CPAP, the levels of pressure are adjusted if the device senses increased airway resistance.

Bilevel positive airway pressure (BiPAP), another type of positive airway pressure, delivers a preset amount of pressure when you breathe in and a different amount of pressure when you breathe out.

CPAP is more commonly used because it’s been well-studied for obstructive sleep apnea and has been shown to effectively treat obstructive sleep apnea. However, for people who have difficulty tolerating fixed CPAP, BiPAP or autotitrating CPAP may be worth a try.

Don’t stop using your positive airway pressure machine if you have problems. Check with your doctor to see what adjustments you can make to improve its comfort. In addition, contact your doctor if you still snore despite treatment, if you begin snoring again or if your weight changes.

Mouthpiece (oral device)

Though positive airway pressure is often an effective treatment, oral appliances are an alternative for some people with mild or moderate obstructive sleep apnea. These devices may reduce your sleepiness and improve your quality of life.

These devices are designed to keep your throat open. Some devices called mandibular advancement device (MAD) keep your airway open by bringing your jaw forward, which can sometimes relieve snoring and mild obstructive sleep apnea. Other devices hold your tongue in a different position.

Mandibular advancement devices not generally recommended for more severe obstructive sleep apnea, although they may be an option if you’re unable to tolerate using a CPAP device.

An mandibular advancement device is worn over your teeth when you’re asleep. It’s designed to hold your jaw and tongue forward to increase the space at the back of your throat and reduce the narrowing of your airway that causes snoring.

Off-the-shelf mandibular advancement devices are available from specialist websites, but most experts don’t recommend them, as poor-fitting mandibular advancement devices can make symptoms worse.

It’s recommended you have an mandibular advancement device made for you by a dentist or orthodontist with training and experience in treating sleep apnea.

An mandibular advancement device may not be suitable treatment for you if you don’t have many – or any – teeth. If you have dental caps, crowns or bridgework, consult your dentist to ensure they won’t be stressed or damaged by an mandibular advancement device.

If you and your doctor decide to explore this option, you’ll need to see a dentist experienced in dental sleep medicine appliances for the fitting and follow-up therapy. A number of devices are available. Close follow-up is needed to ensure successful treatment.

Surgery or other procedures

Surgery to treat obstructive sleep apnea isn’t routinely recommended because evidence shows it’s not as effective as CPAP at controlling the symptoms of the condition. Surgery also carries the risk of more serious complications.

Surgery is usually only considered as a last resort when all other treatment options have failed, and also if the condition is severely affecting your quality of life.

A range of surgical treatments have been used to treat obstructive sleep apnea. These include:

• Tonsillectomy – where the tonsils are removed if they’re enlarged and blocking your airway when you sleep
• Adenoidectomy – where the adenoids, small lumps of tissue at the back of the throat above the tonsils, are removed if they’re enlarged and are blocking the airway during sleep.
• Uvulopalatopharyngoplasty is a procedure in which your doctor removes tissue from the back of your mouth and top of your throat. Your tonsils and adenoids may be removed as well. Uvulopalatopharyngoplasty usually is performed in a hospital and requires a general anesthetic. Doctors sometimes remove tissue from the back of the throat with a laser (laser-assisted uvulopalatoplasty) or with radiofrequency energy (radiofrequency ablation) to treat snoring. These procedures don’t treat obstructive sleep apnea, but they may reduce snoring. Uvulopalatopharyngoplasty used to be a common surgical treatment for obstructive sleep apnea, but it’s performed less often nowadays. This is because more effective treatments are available, such as CPAP. This type of surgery can mean you’re unable to use a CPAP device properly in the future if you need to.
• Upper airway stimulation. This new device is approved for use in people with moderate to severe obstructive sleep apnea who can’t tolerate CPAP or BiPAP. A small, thin impulse generator is implanted under the skin in the upper chest. The device detects your breathing patterns and when necessary, stimulates the nerve that controls movement of the tongue. A study on the device found that it led to significant improvement in obstructive sleep apnea symptoms and improvements in quality of life.
• Jaw surgery. In this procedure, called maxillomandibular advancement, the upper and lower parts of your jaw are moved forward from the rest of your facial bones. This enlarges the space behind the tongue and soft palate, making obstruction less likely.
• Tracheostomy. Surgical opening in the neck. You may need this form of surgery if other treatments have failed and you have severe, life-threatening obstructive sleep apnea. In this procedure, your surgeon makes an opening in your neck and inserts a metal or plastic tube through which you breathe. Air passes in and out of your lungs, bypassing the blocked air passage in your throat.
• Weight loss (bariatric) surgery – where the size of the stomach is reduced if you’re severely obese and this is making your sleep apnoea worse
• Soft palate implants. This minimally invasive treatment involves placement of three tiny polyester rods in the soft palate. These inserts stiffen and support the tissue of the soft palate and reduce upper airway collapse and snoring. This treatment is recommended only for people with mild obstructive sleep apnea. The National Institute for Health and Care Excellence (NICE) has said soft palate implants are safe, but they’re not currently recommended for treating obstructive sleep apnea as there’s a lack of evidence about their effectiveness. However, this form of treatment is recommended for treating snoring associated with obstructive sleep apnea in exceptional cases.

Other types of surgery may help reduce snoring and sleep apnea by clearing or enlarging air passages, including:

• Nasal surgery to remove polyps or straighten a crooked partition between your nostrils (deviated septum)