Sleep apnea: what is it, symptoms, test, treatment

last updated: Jun 16, 2021

9 min read

Do you often wake up feeling tired even though you slept for at least seven hours? Have you been told you snore loudly? If you have these symptoms, you may have sleep apnea.

Sleep apnea is a medical condition that causes abnormal breathing when you sleep and can result in serious long-term health consequences. Learn more about sleep apnea, its symptoms, causes, and treatments so you can sleep better. 


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What is sleep apnea?

Even while you sleep, you keep breathing. It’s normal for your breathing to slow down when you’re fast asleep. Sleep apnea, however, is when your breathing during sleep isn’t just slowed down—it’s abnormal. Some people have many long pauses between breaths. These pauses affect your oxygen supply to your body, leading to poor sleep quality and may lead to other serious health conditions (Cumpston, 2020).

What are the types of sleep apnea?

There are three types of sleep apnea, each with different causes. Though they all involve abnormal paused breathing during sleep, it’s essential to know which kind of sleep apnea you have to get the proper treatment for your symptoms (Javaheri, 2017).

  • Central sleep apnea (CSA) is when your brain doesn’t send the complete message to your breathing muscles to work properly when you sleep. Your breaths are slower and not deep enough to oxygenate you properly (Javaheri, 2017).

  • Obstructive sleep apnea (OSA) is when your breathing is physically blocked somewhere along the path of your airway. This blockage stops your breathing (Cumpston, 2020).

  • Mixed sleep apnea or complex sleep apnea is when you have both CSA and OSA (Javaheri, 2017).

Who gets sleep apnea?

Anyone can get sleep apnea at any age. 

Obstructive sleep apnea is one of the most common breath-related sleep disorders. When people say they have sleep apnea, they usually mean they have obstructive sleep apnea. OSA primarily affects adult men and post-menopausal women, but it can affect children and adults of all gender identities. Between 15–30% of adult males and 10–15% of females have obstructive sleep apnea (Cumpston, 2020). 

Between one and five percent of children are diagnosed with OSA (Paruthi, 2020).

Central sleep apnea is not as common, with less than one percent of older adults with this diagnosis. More men than women are diagnosed with CSA (Donovan, 2016).

What causes sleep apnea?

Sleep apnea has multiple causes, including your body’s physical structure or if you have certain medical conditions. Because obstructive sleep apnea is when your airway is blocked when you sleep, you may be at increased risk for OSA if you have any of the following factors:


The way your entire upper airway is shaped and positioned can predispose you to develop obstructive sleep apnea. 

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The upper airway consists of your tongue, soft palate at the top of your mouth, tonsils, the soft tissue in the back of your throat, lower jaw, and neck. Some people have a naturally small airway because they have enlarged tonsils or a large tongue. When children have sleep apnea, it is usually enlarged tonsils or dental/oral problems (Cumpston, 2020). 

The way you sleep also puts you at higher risk for OSA. If you sleep on your back, the soft tissue in the back of your throat can fall backward and block your airflow. If you have nasal congestion due to allergies, cold, or flu, you may be using your mouth to breathe. This makes it more likely for you to develop OSA (Cumpston, 2020).

Sleeping relaxes all your muscles, including the ones in your mouth. When you sleep, your throat needs to stay open. With sleep apnea, your soft tissues may collapse and block your breathing (Cumpston, 2020). 


Obesity is a significant risk factor for OSA. There are estimates that over 60% of OSA cases are due to obesity. Being overweight narrows your airway and strains your respiratory system. If you have a large neck (17 inches or bigger for men and 16 inches or bigger for women), it can press on the airway, making it harder to breathe at night. Children who have obesity also have a higher risk of OSA (Ogilvie, 2017).


Your gender also has an impact. Men are more likely to have OSA than women, as biologically born women have slightly different upper airway architecture than men. However, when women are pregnant and the baby's weight presses upward in the third trimester, they can have OSA. Post-menopausal women have hormonal changes that can lead to an increased OSA risk (Wimms, 2016). 


OSA is slightly more common in Blacks, Hispanics, and Native Americans than in Caucasians (Rundo, 2019).

Family history 

If your family has a history of OSA, you’re more likely to develop OSA (Rundo, 2019).


Alcohol and sedatives relax the soft tissue in the throat. Using these substances routinely raises your risk for OSA. People who smoke also have an increased risk because tobacco inflames and narrows the upper airway (Rundo, 2019).

Medical conditions 

Multiple medical conditions can also increase your risk for OSA. For example, if you have hormonal issues that affect your weight, like hypothyroidism, you’re at higher risk for OSA (Thavaraputta, 2019). People diagnosed with acromegaly or excess growth hormone may have swelling of the soft tissue of their upper airway due to their disease. This can cause OSA (Vouzouneraki, 2018). Women diagnosed with polycystic ovary syndrome (PCOS) are also at risk for sleep apnea (Rundo, 2019).

You may be at increased risk for sleep apnea if you've been diagnosed with heart or kidney failure, genetic disorders like Down syndrome, or have neuromuscular disorders like muscular dystrophy (Rundo, 2019).

Central sleep apnea doesn't have breathing blockages. People with CSA have abnormalities with communication within or from the brain. Usually, when carbon dioxide rises in the body, the brain sends a message to the breathing muscles to take in more oxygen with deeper and faster breaths. When a person has CSA, their brain doesn't recognize the higher carbon dioxide levels in the body, and their breathing is slow and shallow (Dempsey, 2019).

Most people with CSA have an underlying health problem like stroke or brain infection. Some opioid medications can have this effect as well. People with heart failure have a higher risk of CSA. Some people develop CSA at high altitudes (higher than 6,000 feet) because of the decreased oxygen levels (Dempsey, 2019).

What are the symptoms of sleep apnea?

When you’re asleep, it’s difficult for you to monitor your breathing. Most people are told of their breathing pauses at night by the people they share sleeping space with—a family member, partner, or roommate (Cumpston, 2020).  

All types of sleep apnea have similar symptoms. People with sleep apnea have trouble breathing or even stop breathing while sleeping for several seconds or as long as one minute. Some people with OSA have loud snoring with snorting, gasping, and choking sounds. In contrast, people with CSA generally do not snore (Cumpston, 2020). 

When people with sleep apnea wake up, they may have a dry mouth or sore throat, morning headache, and a bad mood. They may find it hard to think clearly, pay attention or concentrate on work. They may feel exhausted and have excessive daytime sleepiness. Almost all of these symptoms happen because of poor sleep and breathing pauses that cause reduced oxygen levels flowing through the body (Cumpston, 2020). 

Some men may find that they frequently wake up to pee during the night (nocturia). People with more severe obstructive sleep apnea usually have this symptom (Maeda, 2016).

What are the effects of sleep apnea on your body?

One of the main issues of sleep apnea is the lack of oxygen due to breathing pauses or shallow, slow breaths. When your oxygen levels drop, it sets off your “fight or flight” response. This causes a cascade of hormones and altered blood flow to increase your heart rate and blood pressure. These processes help wake you up to gulp in some oxygen. 

Sleep apnea also causes sleep deprivation or lack of restorative sleep. Sleep deprivation and the inflammation that often results can cause physical and mental health problems (West, 2018).

Physical health problems

Untreated sleep apnea raises the risk of heart-related problems, including high blood pressure or hypertension, arrhythmias, heart attack, heart disease, stroke, atrial fibrillation, and elevated heart rate. It can cause asthma and chronic kidney disease. Some people develop metabolic disorders like high blood sugar and type 2 diabetes (West, 2018).

Pregnant women can have high blood pressure (preeclampsia), pregnancy diabetes (gestational diabetes), or give birth to a baby with low birth weight. Other people with undiagnosed sleep apnea can have eye problems like dry eye or glaucoma. People who lack sleep are more at risk for kidney, pancreatic, and skin cancer (West, 2018).

Mental health problems

Untreated sleep apnea affects concentration, focus, fine motor skills, and the ability to form and process information and create memories. Children with sleep apnea may be diagnosed with learning disabilities. There is an increased risk of dementia in older adults with sleep apnea (West, 2018). 

How is sleep apnea diagnosed?

When you have your appointment with your healthcare provider, they may ask you about the symptoms you’ve been having, your family history of sleep apnea, and any prescribed or recreational medications (especially opioids) you may be taking. They’ll also ask you about any underlying medical conditions you may have, including complications of untreated sleep apnea like high blood pressure, type 2 diabetes, or atrial fibrillation. You may be asked to complete the Epworth Sleepiness Scale, a survey to see how sleepiness affects you (Rundo, 2020).

You will then have a complete physical exam with particular attention paid to your throat and neck. Your healthcare provider may check your tonsil and tongue size, jaw size and structure, and neck size as these may affect your breathing. They will check your heart, lungs, reflexes, and weight. You may have blood tests to see if you have any hormonal problems that could cause sleep apnea-like symptoms (Rundo, 2020).

Depending on the results, your healthcare provider may refer you to a sleep specialist for a sleep study. Sleep studies can be performed at a sleep center or your home. 

A sleep study, called a polysomnogram, identifies how many apnea events—where your breathing slows down or even stops—happen during your sleep. It tracks your heart and brain activity and your blood oxygen levels while you sleep (Cumpston, 2020).

The sleep study also records your breathing muscle activity to determine what type of sleep apnea you have. If you have obstructive sleep apnea, your breathing muscles will be more active as they work to open your blocked airway. If you have central sleep apnea, your chest muscles will be less active because they aren’t receiving the signal that they need to work harder to clear carbon dioxide (Cumpston, 2020). 

Your sleep apnea score is based on how many apnea events you have in an hour. Mild sleep apnea has from five to 14 apnea events, moderate has from 15 to 29 events, and severe has 30 or more apnea events in an hour (Rundo, 2019).

Treating sleep apnea

If you’ve been diagnosed with sleep apnea, treatment can help you improve your sleep and lower your risk of health problems. Your healthcare provider may treat your allergies or change your prescribed medications if they exacerbate sleep apnea. They may recommend several treatment options, including medication and lifestyle changes and, if necessary, a device to keep your airway open while you sleep (Rundo, 2019).

Lifestyle modifications

The following lifestyle modifications can make a big impact on your sleep apnea (Chang, 2020):

  • Lose weight: The most important lifestyle modification you can make to treat your sleep apnea is to lose weight if you have excess weight. Obesity is a significant risk factor for obstructive sleep apnea.

  • Move your body: Exercise helps to rev up your metabolism to help you lose any excess weight and improve your overall health.

  • Limit your alcohol: If you do drink alcohol, stop at least three hours before bed. Alcohol relaxes all your muscles, including the ones in your throat. This makes you more likely to snore and increases your risk for sleep apnea.

  • Improve your sleep hygiene: Develop better sleeping habits by sleeping on your side rather than your back, establishing a set bedtime routine, sleeping in a cool, dark, and quiet room, and limiting screen time before bed.

  • Stop smoking: Tobacco inflames your throat and narrows your airway, so quitting smoking is important if you have sleep apnea. 

Physical therapy

Orofacial myofunctional therapy helps children and adults strengthen the muscles of the upper airway, face, and mouth. This type of physical therapy can help people with mild to moderate sleep apnea (de Felicio, 2018). 


If these lifestyle changes don’t successfully treat your symptoms of sleep apnea, your healthcare provider or sleep specialist may recommend using a continuous positive airway pressure (CPAP) machine at night. This machine pushes air through a mask into your airway, so it stays open while you sleep. If your upper airway anatomy causes your sleep apnea, the sleep specialist may recommend a mouthpiece that keeps your tongue or jaw in a specific position. Mouthpieces are custom-made to fit you (Chang, 2020).

If you’ve been diagnosed with CSA or mixed sleep apnea, the focus will be on treating the underlying health condition causing the breathing issues. You may also receive supplemental oxygen or use a CPAP or BiPAP machine at night (Dempsey, 2019).


Some people need more help to manage their sleep apnea. The U.S. Food and Drug Administration approved an implant that passes a slight current to specific muscles to keep the airway open while sleeping. This surgical procedure might help those with severe obstructive sleep apnea. More research is needed to see the benefits of this treatment for central sleep apnea. Another surgical procedure uses a nerve stimulator that helps position the tongue in a certain way, so the airway stays open (Chang, 2020).

Other surgeries for sleep apnea include tonsillectomy or uvulopalatopharyngoplasty, to remove some of the soft tissue blocking the airway, as well as nasal surgery, tongue advancement, or tongue base reduction (Chang, 2020). 

Sleep easy

Sleep apnea doesn’t just make you feel tired, it has long-term health consequences. If you have been diagnosed with sleep apnea, it is crucial that you adopt and maintain healthy lifestyle habits and use your prescribed treatment. Help is available, and your sleep apnea can be manageable. 


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

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Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

June 16, 2021

Written by

Tobi Ash, MBA, RN, BSN

Fact checked by

Steve Silvestro, MD

About the medical reviewer

Dr. Steve Silvestro is a board-certified pediatrician and Associate Director, Clinical Content & Education at Ro.