Sleep Apnea

What Is Sleep Apnea? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Katherine Lee
By Medically Reviewed by 
Reviewed:
Medically Reviewed
Sleep apnea is a common and serious sleep disorder that causes your breathing to become shallow or stop completely during sleep. In some cases, this pause in breathing (called apnea) can last 10 seconds or longer, and it can occur as often as 30 times or more in an hour.

Though certain chronic health problems increase sleep apnea risk and make it more prevalent in older individuals, factors such as enlarged tonsils or having a thicker neck and narrow airway can cause sleep apnea to develop at any age (including childhood).

Despite the condition being common, it often goes undiagnosed because many of the typical signs and symptoms of sleep apnea — loud snoring, gasping for air, and interruptions in breathing — occur during sleep, when individuals may not realize what’s happening.

What makes the underdiagnosis of sleep apnea problematic is that the condition, if untreated, can lead to numerous health problems, including cardiovascular diseases, diabetes, and even increased risk of sudden death. And because this sleep disorder is associated with chronic daytime sleepiness, it’s been found to be the cause of a number of workplace and vehicular accidents.

Additionally, there are negative mental effects that accompany sleep apnea, including impaired focus, concentration, memory, and impulse control, as well as low energy levels.

Correctly identifying and treating sleep apnea can also play a crucial role in public safety, says Ronald Chervin, MD, a professor of sleep medicine and neurology at the University of Michigan in Ann Arbor.

“Sleep apnea is a public health problem,” he says.

Common Questions & Answers

Can you die from sleep apnea?
Sleep apnea is most dangerous when it’s not properly treated, because the condition strains your cardiovascular system (increasing your risk of atrial fibrillation, heart disease, stroke, and other conditions). Untreated or mismanaged sleep apnea also increases accident risk because of excessive daytime fatigue and sleepiness.
How common is sleep apnea?
Nearly 30 million people in the United States are estimated to have obstructive sleep apnea. The disorder is more common in men: Approximately 14 percent of males have sleep apnea, and 5 percent of females have the condition.
Do I need a breathing machine to treat sleep apnea?
Some mild cases of sleep apnea can be managed with lifestyle changes (like weight loss, smoking cessation, and exercise). But many cases require further treatment — the mainstay of which is continuous positive airway pressure, or CPAP, breathing machines you wear while you sleep.
Are there home remedies that help with sleep apnea?
For mild cases of sleep apnea, lifestyle changes alone may be enough to manage symptoms. And for people who do require further treatment, these lifestyle changes can help with outcomes, too. They include: losing weight, sleeping on your side, avoiding alcohol late in the day, avoiding certain drugs and medications, quitting smoking, and exercising.
What are the risks of not treating sleep apnea?
Undiagnosed, untreated, or mismanaged sleep apnea can lead to chronic sleepiness in the daytime and to problems with memory, attention, irritability, and mood. Mismanaging or not treating the condition can also increase the risk of metabolic syndrome, heart disease, stroke, diabetes, glaucoma, pregnancy complications, accidents, and more.

The Three Different Types of Sleep Apnea

All sleep apnea is characterized by repeated interruptions in breathing, but the underlying cause of the interruptions varies. The main types of sleep apnea are:

Obstructive Sleep Apnea This is the most common form of sleep apnea, and it occurs when there is a partial or complete obstruction of the airway, says Neeraj Kaplish, MD, director of sleep laboratories at the University of Michigan in Ann Arbor.

When we sleep, the muscles in our body, including those in our throat, naturally become relaxed. Normally, the airway remains open enough for air to enter freely during sleep. But in cases of obstructive sleep apnea, your airway is too narrow (sometimes because you were born with a thicker neck and narrower airway, and other times because body weight creates extra fat deposits in the throat), and when you relax your muscles in your sleep, the tissues in the back of your throat can block your airway.

This airway blockage can cause loud snoring, snorting, or gasping for air during sleep (though not everyone with obstructive sleep apnea snores, and not everyone who snores has sleep apnea).

RELATED: What Makes Someone a Light or Heavy Sleeper?

Central Sleep Apnea This type of apnea occurs when something goes awry with the brain’s normal signaling to muscles that control breathing in the body, causing breathing to repeatedly stop or become very shallow.

Unlike obstructive sleep apnea, which is caused by a physical blockage, central sleep apnea is a neurological problem, says Robson Capasso, MD, professor of otolaryngology and head and neck surgery at Stanford University School of Medicine in California.

People who have central sleep apnea often have an illness or condition that affects the brain stem, which is the area of the brain that controls breathing. Health conditions linked to central sleep apnea include stroke, heart failure, kidney problems, or a brain lesion or disorder.

Certain medications that interfere with how well the brain sends signals to muscles, such as sedatives, opioids, or benzodiazepines, can also play a role in central sleep apnea, says Dr. Capasso.

Complex Sleep Apnea Syndrome Complex sleep apnea happens when someone has both obstructive sleep apnea and central sleep apnea at the same time.

People who have this type of sleep apnea often seem at first to only have obstructive sleep apnea, but when they’re treated for that condition and symptoms don’t improve as they should, doctors will suspect that central sleep apnea is also present.

Learn More About the Three Types of Sleep Apnea

Signs and Symptoms of Sleep Apnea

Common signs and symptoms of this condition include:

  • Feeling exhausted and sleepy during the day despite getting seven or more hours of sleep at night
  • Waking up with dry mouth
  • Experiencing morning headaches
  • Having trouble with attention, concentration, and memory
  • Irritability
  • Having decreased sex drive or sexual dysfunction
  • Depression

In addition, your partner or family members may tell you that they witnessed one or more of the following:

  • Chronic snoring that may be extremely loud
  • Repeated pauses in breathing followed by snorting and gasping for air

Learn More About Sleep Apnea Symptoms

Causes and Risk Factors of Sleep Apnea

Sleep apnea is caused by the muscles and soft tissues in the throat relaxing too much during sleep, repetitively blocking your airway. Generally, the anatomy and physical structure of your throat or, in some cases, certain medical conditions, cause this to happen.

It’s important, however, to understand that there are certain risk factors that can increase your chances of having sleep apnea, some that you can avoid, and others (like family history of the condition) that you cannot. Some of the common sleep apnea risk factors are:

  • Obesity
  • Having large adenoids or tonsils
  • Having a lower jaw that’s misaligned or smaller than the upper jaw
  • A family history of sleep apnea
  • Age (sleep apnea can affect people of any age but is more common in older adults)
  • Type 2 diabetes
  • High blood pressure
  • Stroke
  • Heart failure
  • Smoking
  • Use of alcohol and certain medications
  • Neuromuscular conditions that interfere with brain signals to airway and chest muscles

Learn More About the Causes and Risk Factors of Sleep Apnea

How Is Sleep Apnea Diagnosed?

To diagnose sleep apnea, your doctor will most likely start by taking your full medical history and conducting a physical examination. Upon reviewing that information, your doctor may recommend a sleep study, also called a polysomnography.

Sleep studies are done during an overnight stay at a sleep disorders clinic. In some cases, they can be done at home, though those tests are limited in what they can measure.

A home sleep test is a simplified version of a polysomnography that typically monitors your breathing (pauses in breathing, how much effort it takes to get air, and whether your breathing is shallow) and oxygen levels. A sleep study done in the lab is more comprehensive, and can measure additional data such as brainwaves; heart rate; how well air flows in and out of your lungs, nose, and mouth; leg movements; and how many times you wake up during the night.

A home sleep test basically measures breathing, not sleep, so it may lead to inconclusive results when used to evaluate sleep apnea. For some people, such as those who have a heart, lung, or neuromuscular condition, a more comprehensive overnight sleep study at a lab may be a better option to diagnose sleep apnea.

Learn More About Diagnosing Sleep Apnea

Prognosis of Sleep Apnea

There are steps you can take to manage your condition and improve your sleep. Getting the right diagnosis and treatment for sleep apnea is crucial since the condition has been associated with a number of health problems, including cardiovascular disease, metabolic disease, and type 2 diabetes, and untreated sleep apnea can be life-threatening.

Research shows that successful treatment of sleep apnea can help reduce the risk of heart and blood pressure problems in people with this condition.

Duration of Sleep Apnea

There’s no cure for sleep apnea, but depending on what’s causing your sleep apnea, you may be able to relieve or resolve certain symptoms over time with treatment or lifestyle changes.

Treatment and Medication Options for Sleep Apnea

In some cases, sleep apnea can be managed with lifestyle changes. Your doctor may recommend that you:

  • Eat right, exercise, and lose weight. Fill your plate with heart-healthy options like vegetables, fruits, and whole grains and get plenty of exercise. Adopting these healthy habits can help you maintain a healthy weight, which is important because obesity can increase your risk for sleep apnea.
  • Stop smoking. Smoking may increase upper airway inflammation and reduce function.
  • Avoid alcohol and certain medications. Don’t take sedatives, opioids, or benzodiazepines,

    and try not to drink, especially close to bedtime, as these substances can relax the muscles in the back of your throat and potentially further interfere with breathing.

  • Do not sleep on your back. Sleeping on your back can increase the likelihood that your tongue and soft palate will fall back into your airway, causing airway obstruction, snoring, and sleep apnea.

RELATED: Weight Loss Plans That Work (and the Fad Diets to Skip)

Many cases of sleep apnea require treatment beyond lifestyle modifications. Typical sleep apnea treatments your doctor may suggest are:

Continuous Positive Airway Pressure (CPAP) The most common treatment is a CPAP machine, which is a device you can use at home that gently forces pressurized air through a mask you wear over your nose and mouth (or just your nose) into your airway to keep it open while you sleep at night. CPAP has been shown to be effective in treating sleep apnea.

Oral Devices Before you try CPAP, or if breathing machines are not working for you, your doctor may suggest an oral device. These mouthpieces, typically custom fit by your dentist, can be particularly helpful for individuals who have obstructive sleep apnea. An oral apparatus can help keep your throat open either by bringing your jaw forward and preventing the tongue from falling back into your airway or by keeping your tongue in a forward position when you lie on your back, and it’s a more portable, simple option than a CPAP machine.

Surgery When lifestyle changes, CPAP, and other sleep apnea treatments are not working for you, your doctor may advise surgery, which is typically performed to either make more room in the throat by removing the tonsils, adenoids, or other tissue in the back of the throat — or to reposition your jaw to open up the airway. In rare and life-threatening cases of sleep apnea, doctors may perform a tracheostomy to insert a breathing tube directly into the trachea. Doctors may also perform weight loss surgery to reduce obesity.

Implants One of the latest sleep apnea treatments that’s showing promise is a device that is surgically implanted underneath the skin of the neck and chest. This pacemaker-like device continuously monitors your breathing patterns while you sleep and delivers mild stimulation to muscles in the respiratory tract to help keep the airway open while you sleep.

Learn More About Treatment Options for Sleep Apnea

Prevention of Sleep Apnea

There are some measures that may be useful in helping to prevent sleep apnea. These include:

  • Eating a heart-healthy diet
  • Losing weight if you are overweight
  • Not smoking (or quitting if you do smoke)
  • Sleeping on your side
  • Getting adequate, good-quality sleep
  • Limiting the amount of alcohol you drink and avoiding sedatives
  • Managing allergies
  • Improving nasal airflow
  • Avoiding mouth breathing (but not using oral tape)

Complications of Sleep Apnea

When you’re unable to have normal sleep cycles that give you a restful, restorative sleep, it can have profound physical, mental, and even emotional consequences.

RELATED: What Happens When You Don’t Sleep

Undiagnosed sleep apnea can lead to chronic sleepiness in the daytime, problems with attention and memory, irritability, and depression. And if someone with sleep apnea is snoring loudly, it can interfere with a partner’s sleep, as well. Over time, untreated sleep apnea may increase your risk of:

And because sleep apnea can lead to sleepiness in the daytime, it can also increase your risk of having an accident. A number of train crashes, road accidents, and other industrial accidents are suspected to have been caused by an operator falling asleep due to sleep apnea.

Many safety advocates and sleep experts, including the American Academy of Sleep Medicine (AASM), have urged groups like the Federal Motor Carrier Safety Administration (FMCSA) and the Federal Railroad Administration (FRA) to have sleep apnea screening requirements to identify the common disorder in truck drivers and train conductors, who need to be alert to do their jobs safely.

Learn More About Sleep Apnea Complications

Research and Statistics: Who Has Sleep Apnea?

Sleep apnea is one of the most common sleep disorders in the United States, affecting the health of millions of Americans. Obstructive sleep apnea is estimated to affect between 2 and 9 percent of adults in the United States.

And the AASM estimates that up to 30 million people have sleep apnea.

The tricky aspect of evaluating just how many people have sleep apnea stems from the fact that many cases are believed to be undiagnosed.

Sleep apnea can occur at any age, but the risk increases with age. Research also consistently shows that obstructive sleep apnea seems to affect more men than women, though the numbers seem to even out more for postmenopausal women.

A review of studies published in 2020 reported that 17 percent of women are affected by obstructive sleep apnea compared with 34 percent of men.

It’s also estimated that sleep apnea is more common in Hispanic, African American, and Asian populations.

Women with undiagnosed sleep apnea face particular challenges. Until recently, sleep apnea was considered to be a condition that primarily affects men, and as a result, it was underdiagnosed and undertreated in women.

Sleep apnea symptoms can look different in women. For instance, some women with sleep apnea don’t snore and don’t experience excessive daytime sleepiness.
A study published in 2019 examined gender differences in sleep apnea.

The researchers analyzed data from 2,057 participants — a little more than half of whom were women — who underwent a comprehensive sleep study.

They measured sleep apnea severity based on the apnea-hypopnea index (AHI) — which is the number of pauses in breathing per hour of sleep — during both REM and non-REM sleep and found that twice as many men as women had a top AHI score of 15 during non-REM sleep. But during the REM phase of sleep, the same number of men and women had a high AHI score. This was important, according to the researchers, because this is the number that doctors believe is the best predictor of a person’s risk for developing hypertension and cardiovascular disease.

The researchers found other differences between men and women with sleep apnea: Women experienced more stable breathing and less collapsing of the airway, and they were more easily roused when the airway began to close during periods of breathing pauses. Researchers noted the need to evaluate sleep apnea differently in women to better diagnose and treat the condition.

Conditions Related to Sleep Apnea

Research has shown that having sleep apnea increases your risk of disorders such as cardiovascular disease (including stroke, high blood pressure, atherosclerosis, and heart failure), diabetes, and depression.

Conversely, people who have cardiovascular disease, including high blood pressure, stroke, and coronary heart disease, are at high risk for obstructive sleep apnea.

Excess weight also appears to have a link to sleep apnea that is reciprocal: People who are overweight or obese have an increased risk for sleep apnea, and people who have sleep apnea seem to be more susceptible to weight gain.

That two-way relationship can apply to losing weight, as well. Weight loss can improve sleep apnea by reducing the fatty deposits in the neck that can contribute to sleep apnea and has also been shown to improve cardiovascular health, daytime sleepiness, high blood pressure, insulin resistance, type 2 diabetes, and quality of life. And losing just 10 to 15 percent of your weight can reduce the severity of obstructive sleep apnea by as much as 50 percent in moderately obese patients.

What’s clear is that getting effective treatment for sleep apnea can improve much more than your sleep — it can impact your health in numerous ways. A review of 27 studies involving over three million participants published in 2017 found that the risk for death due to cardiovascular disease was reduced to normal levels in people with sleep apnea when they were treated with CPAP therapy.

Resources We Love

Favorite Orgs for Essential Sleep Apnea Info

American Sleep Apnea Association (ASAA)

ASAA promotes awareness of sleep apnea through advocacy and education. Learn how to get involved on their website. ASAA runs its Alert, Well, and Keeping Energetic (A.W.A.K.E.) support groups for people with sleep apnea across the country. And the organization has a CPAP assistance program that helps provide CPAP equipment to patients who cannot otherwise afford it.

Federal Motor Carrier Safety Administration (FMCSA)

FMCSA is the federal government agency in the United States responsible for safety oversight of commercial motor vehicles. The agency has sponsored research documenting incidence of sleep apnea in commercial truck drivers and has led efforts to increase sleep apnea screening and education for them.

National Heart, Lung, and Blood Institute (NHLBI)

NHLBI is one of the institutes that makes up the U.S. Department of Health and Human Services National Institutes of Health. Check out the NHLBI’s sleep apnea page for information on the condition and how to manage it. You’ll also find information about new and ongoing research and how to participate in clinical trials.

American Academy of Sleep Medicine (AASM)

The AASM defines itself as the “only professional society dedicated exclusively to the medical subspecialty of sleep medicine” and is composed of physicians, scientists, and other healthcare professionals who work to advance sleep medicine and promote sleep health to improve people’s lives.

Favorite Sleep Apnea Podcast

Breathe Better, Sleep Better, Live Better

Episodes of this podcast cover topics ranging from why sleep apnea treatments don’t work for some people, to sleep apnea myths, to how our diets affect sleep disorders. The podcast’s producer and creator is Steven Y. Park, MD, an assistant professor of otorhinolaryngology and head and neck surgery at Albert Einstein College of Medicine in the Bronx, New York. Dr. Park has written books on sleep and sleep disorders, and his podcast and work focuses on helping people sleep better and address potential sleep disorders.

Favorite Online Support Networks

CPAPTalk

This online forum is a place for people with sleep apnea and the medical providers who treat them to ask questions and get answers. The forum includes a section devoted to user-generated product reviews. There’s also a directory of providers, sleep labs, product providers, and support groups you can search by geographical area.

MyApnea.org

This online community of individuals who have sleep apnea and the doctors who treat them offers an online forum to share advice about managing sleep apnea. The website also features a blog with posts about patient stories and new research.

Editorial Sources and Fact-Checking

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