Obstructive Sleep Apnea

Written by Rebecca Levi

Reviewed by Dr. Michael Breus

Our Editorial Process
Updated Regularly
Table of Contents

Obstructive sleep apnea (OSA) is a common sleep disorder that can lead to serious consequences if left untreated. It’s estimated that 30 million or more people currently live with OSA, yet around 80% remain undiagnosed. 

People with obstructive sleep apnea may snore loudly at night and feel overly sleepy during the day. However, many don’t recognize their symptoms or realize the potential impact of OSA on their health. Fortunately, working with a doctor to find an appropriate treatment can help reduce the symptoms and potential complications of obstructive sleep apnea.

Understanding how obstructive sleep apnea affects breathing and overall health can help people recognize when it’s time to seek medical attention. Learn more about the symptoms and causes of obstructive sleep apnea, as well as how the condition is diagnosed and treated.

What Is Obstructive Sleep Apnea? 

Obstructive sleep apnea is a sleep disorder in which a person’s airway narrows or closes as they sleep. This causes their breathing to become restricted and briefly stop. Pauses in breathing make blood oxygen levels drop and carbon dioxide levels rise, triggering the sleeper to wake up so they can start breathing again.

OSA is one of two types of sleep apnea. The other type, called central sleep apnea (CSA), also involves repeated pauses in breathing. CSA is caused by the brain failing to send signals that regulate breathing. Most people with sleep apnea have signs of both OSA and CSA. The diagnosis of one or the other is based on a person’s most predominant symptoms. 

What Causes Obstructive Sleep Apnea?

Obstructive sleep apnea is caused by blockages in the airway during sleep. 

As a person falls asleep, the tissues in their mouth and throat begin to naturally relax, which can reduce the space in their airway. Normally, these changes are of little consequence and don’t affect a person’s breathing pattern, oxygen levels, or sleep.

But for people at risk of obstructive sleep apnea, these natural changes in the throat can cause the airway to become blocked, either partially or completely. Blockages can last for a few seconds to a minute or more, causing the sleeper to wake up in order to breathe.

Get your at-home sleep apnea test now
Get your at-home sleep apnea test now

What Could Increase Your Risk of Obstructive Sleep Apnea?

Although anyone can develop this condition, a variety of risk factors increase a person’s susceptibility to airway blockages and the development of obstructive sleep apnea.

  • Age: After young adulthood, the risk of developing obstructive sleep apnea increases and then peaks by the time people reach their 70s. 
  • Sex: Males are two to three times more likely to develop obstructive sleep apnea. The risk of obstructive sleep apnea in females increases when they near or begin menopause.
  • Body weight: The likelihood of developing obstructive sleep apnea increases along with a higher body mass index (BMI), which is a method of calculating body fat according to a person’s weight and height. An estimated 60% to 70% of people with OSA have obesity.
  • Physical characteristics: Certain physical features, like a small jaw or large tonsils, increase the chances of obstructive sleep apnea.
  • Smoking: Tobacco smoking may increase the risk of OSA and can also make breathing disruptions worse.
  • Family history: The risk of obstructive sleep apnea may be higher for people with family members who snore or have OSA. This link could be related to genetics or to shared living conditions within a family.
  • Nasal congestion: Having a stuffy or congested nose can double the risk of obstructive sleep apnea.

The risk of obstructive sleep apnea is also increased by conditions that affect a person’s physical health, such as pregnancy, and certain medical conditions including:

  • Heart failure
  • High blood pressure
  • Kidney disease
  • Stroke
  • Chronic obstructive pulmonary disease (COPD)
  • Underactive thyroid
  • Parkinson’s disease

In children, obesity and enlarged adenoids or tonsils are the main risk factors for obstructive sleep apnea. The adenoids and tonsils are tissues in the back of the throat that help combat infections. When these tissues are larger, they reduce the size of the airway and make it more prone to blockage during sleep.

What Are the Symptoms of Obstructive Sleep Apnea?

The symptoms of obstructive sleep apnea vary from person to person. While some people have no symptoms or are unaware of them, two of the most common OSA symptoms are snoring and daytime sleepiness.

Snoring is caused by air being pulled through a narrow airway as people breathe while they sleep. Around 80% to 90% of people with obstructive sleep apnea snore, but not everyone who snores has OSA. A doctor’s assessment is the only way to tell if snoring is caused by OSA.

As many as 58% of people with OSA experience excessive daytime sleepiness. They may feel tired all day long or only at times when they are not active. People with OSA may find themselves dozing off at work, while watching TV, or even while driving

Additional signs and symptoms of obstructive sleep apnea include:

  • Restless or unrefreshing sleep
  • Realistic, odd, or scary dreams
  • Waking up at night needing to urinate
  • Choking, gasping, or snorting during sleep
  • Morning headaches
  • Difficulty concentrating
  • Mood changes

While obstructive sleep apnea can’t be diagnosed based on symptoms alone, recognizing symptoms can be a crucial step to getting medical care. If you’re unsure about your own nighttime breathing, talk to a bed partner, roommate, or caregiver about whether they have noticed any concerning signs while you sleep. 

When you lie on your back all of the anatomy falls to the back of the throat. What happens? It makes the airway more narrow, which makes the air move faster, which makes it easier to vibrate the muscles. If it gets even worse, it causes an obstruction and sleep apnea.
Dr. Michael Breus

Signs to Look For in Adults

If someone in your life shows signs of sleep apnea, talk to them about seeking an assessment from a medical professional.

  • Loud snoring, gasping, or choking: Note any loud, frequent, or severe breathing issues during sleep. These include snoring or brief pauses in breathing, as well as observing the sleeper making a gasping, snorting, or choking sound.
  • Restless sleep: Take note if a person appears to be tossing and turning at night or waking up repeatedly. Many people living with undiagnosed obstructive sleep apnea mistake these symptoms for insomnia.
  • Daytime sleepiness: Keep track of when, and to what degree, a person is tired. People with undiagnosed OSA may think being tired throughout the day is normal, or they may believe their sleepiness is caused by aging or working too much. 

Signs to Look For in Children

The symptoms of sleep apnea in children can be different from adults. Parents and caregivers who are concerned about their child’s nighttime breathing should also take note of loud or frequent snoring. But other signs and symptoms of obstructive sleep apnea in children include:

Getting Obstructive Sleep Apnea Diagnosed

Talk to your doctor if you are concerned about obstructive sleep apnea. If your doctor suspects OSA based on your symptoms, they may refer you to a specialist in sleep medicine.

To diagnose obstructive sleep apnea, a sleep specialist will consider a person’s medical history, the findings of a physical exam, and the results of a sleep study.

Medical History and Physical Exam

A doctor typically begins an evaluation for obstructive sleep apnea by asking questions related to a person’s symptoms and medical history.

During a physical exam, the doctor assesses a person’s body mass index and any signs of related complications such as high blood pressure. Doctors may also consider a person’s Mallampati classification, which is a way of measuring how narrow a person’s airway appears during an exam.

Sleep Study

A sleep study, conducted overnight in a specialized sleep laboratory, can confirm a diagnosis of obstructive sleep apnea. During a sleep study, a sleeper is monitored by a variety of devices that measure and record certain body functions. Measurements include breathing patterns, the level of oxygen in the blood, and sleeping position. 

At-Home Sleep Apnea Test

In some cases, a doctor may recommend a home sleep apnea test instead of a study in a sleep laboratory. A home sleep apnea test records fewer measurements than an in-lab sleep study and may not detect mild sleep apnea. But home testing may be an option when doctors suspect moderate or severe sleep apnea that isn’t complicated by another medical condition. 

If a doctor continues to suspect obstructive sleep apnea after a negative or inconclusive home sleep apnea test, they may recommend an in-lab sleep study as a next step.

Obstructive Sleep Apnea Severity

When a doctor diagnoses obstructive sleep apnea, they classify the condition’s severity based on a person’s symptoms and apnea-hypopnea index (AHI). The AHI is the average number of disturbed breathing episodes during each hour of a sleep study. 

Knowing the severity of a person’s obstructive sleep apnea helps doctors determine the best treatment. Obstructive sleep apnea may be classified as mild, moderate, or severe.

Apnea-Hypopnea Index (AHI) in Adults


5 to 14

  • No symptoms in some cases
  • Sleepiness during monotonous activities


15 to 30

  • Disrupted sleep
  • Impaired daily function


More than 30

  • Daytime sleepiness that gets in the way of normal activities
  • Falling asleep often when seated

What Could Happen if Obstructive Sleep Apnea Goes Undiagnosed?

Obstructive sleep apnea can lead to potentially serious consequences if left untreated. Possible complications of obstructive sleep apnea include:

  • Motor vehicle accidents
  • Reduced attention span and memory
  • Mood changes and depression
  • Sexual dysfunction
  • Heart disease and stroke
  • Type 2 diabetes

These complications may be caused by several factors related to sleep apnea, including the effects of sleep loss, repeated drops in the amount of oxygen in the blood, and changes in heart rate and blood pressure. 

Obstructive Sleep Apnea Treatments and Devices

Obstructive sleep apnea is treated as a chronic condition needing long-term, nightly treatment. Treatment is aimed at restoring normal breathing, enhancing sleep quality, and relieving other symptoms. 

To treat obstructive sleep apnea, doctors typically recommend positive airway pressure (PAP) therapy in combination with lifestyle changes. If people aren’t able to tolerate these treatments or the treatments aren’t helping, doctors may recommend oral appliances or surgery.

PAP Therapy for Obstructive Sleep Apnea

Positive airway pressure therapy keeps the airway open by pumping pressurized air into the upper airway from a bedside machine. PAP therapy can reduce breathing interruptions in most people with OSA and is considered the cornerstone of treatment by sleep experts.

The most common types of PAP therapy for OSA are CPAP, BiPAP, and APAP.

Emerging alternatives to CPAP therapy may be options for people who can’t tolerate, or don’t benefit from, other PAP therapies. One of these alternatives, called expiratory positive airway pressure (EPAP), doesn’t require a bedside machine. Instead, EPAP devices are inserted into the nostrils and help keep the airway open using pressure created by a person’s own breath.

Oral Appliances for Obstructive Sleep Apnea

Oral appliances for sleep apnea are devices that are inserted into the mouth to shift the jaw and tongue forward, which lowers the chances of airway blockage. While these devices are less effective than CPAP in treating obstructive sleep apnea, they may be helpful for reducing snoring and treating mild OSA.

Surgery for Obstructive Sleep Apnea

Sleep apnea surgery can make the airway larger or prevent it from becoming blocked during sleep. Doctors may recommend surgery when other treatments aren’t helping, or if they believe surgery could make CPAP therapy more effective. 

While surgery can provide significant benefits for some people, it is rarely able to cure obstructive sleep apnea in adults.

For children with obstructive sleep apnea, surgery may be the first treatment they receive. Many children have enlarged adenoids and tonsils that can block their upper airways while they sleep. Removing these tissues may keep the airway open and improve nighttime breathing.

Lifestyle Changes for Obstructive Sleep Apnea

Lifestyle adjustments can be an important part of OSA care and are often recommended along with medical treatment like CPAP therapy.

Exercise and weight loss may be recommended for some people with obstructive sleep apnea. Losing weight through dietary changes, exercise, or weight loss surgery can reduce breathing issues and ease daytime symptoms.

Shifting sleeping positions may also help some people. People who have obstructive sleep apnea that gets worse when they sleep on their backs should consider trying to sleep on their sides. 

Alcohol can aggravate obstructive sleep apnea and snoring, make daytime symptoms worse, and increase the risk of accidents. For these reasons, doctors may recommend that people with obstructive sleep apnea reduce their alcohol consumption or avoid alcohol altogether. 

It’s also a good idea to review medication use with a doctor, as certain medications can make sleep apnea worse.

Living With Obstructive Sleep Apnea 

For many people, working with a doctor to diagnose and treat obstructive sleep apnea can provide relief from symptoms, reduce potential complications, and improve their quality of life. Because these treatments often require adjustments to daily habits, it can take time for people to get used to living with obstructive sleep apnea. 

When starting CPAP therapy, it’s normal to feel uncomfortable with the mask, air pressure, or the noise from the machine. Since the CPAP machine must be used every night to be effective, people should promptly discuss any concerns or problems using a CPAP machine with their doctors.

Sleep hygiene can help anyone living with obstructive sleep apnea get sufficient and high-quality rest. Improving sleep hygiene means practicing healthy sleep habits such as:


About The Author

Rebecca Levi

Staff Writer, Sleep Health

With a bachelor’s degree in anthropology from Indiana University Bloomington, Rebecca enjoys making accurate, up-to-date health information accessible to all readers. As a freelance writer and editor, she has covered everything from healthcare and experimental music to education. Rebecca lives in Tennessee, where she spends her free time reading, writing fiction, and making music.

  • Position: Side sleeper
  • Temperature: Cold Sleeper
  • Chronotype: Dolphin

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