What Is Sleep Apnea?

What Is Sleep Apnea?
Everyday Health
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Updated on January 29, 2025
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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 a thicker neck and narrow airway can cause sleep apnea to develop at any age (including childhood).

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

Left untreated, sleep apnea can lead to health problems, including heart disease, diabetes, and even an increased risk of sudden death. Because sleep apnea is associated with chronic daytime sleepiness, it can lead to workplace and vehicular accidents.

Types of Sleep Apnea

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

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, the 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 relax. 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).


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, a 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.

Signs and Symptoms of Sleep Apnea

Common signs and symptoms of this condition include:

  • Exhaustion and sleepiness during the day despite seven or more hours of sleep at night
  • Dry mouth in the morning
  • Morning headaches
  • Trouble with attention, concentration, and memory
  • Irritability
  • 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

Causes and Risk Factors of Sleep Apnea

Sleep apnea occurs when the muscles and soft tissues in the throat relax 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 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.

Common risk factors include:

  • Obesity
  • Large adenoids or tonsils
  • 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

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.

Duration of Sleep Apnea

There’s no cure for sleep apnea, but depending on what’s causing it, you may be able to relieve or alleviate symptoms with treatment or lifestyle changes.

Treatment and Medication Options for Sleep Apnea

Treatment for sleep apnea ranges from lifestyle interventions like losing weight to surgery for extreme cases.

Lifestyle changes In some cases, sleep apnea can be managed with lifestyle interventions. 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. These healthy habits can help you maintain a healthy weight, which is important because obesity increases the risk of 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 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.
Medication The U.S. Food and Drug Administration (FDA) recently approved the first medication for obstructive sleep apnea. This drug, Zepbound (tirzepatide), can be used to treat severe obstructive sleep apnea in adults with obesity. The FDA said Zepbound should be used in combination with a low-calorie diet and physical activity.

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 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.

Prevention of Sleep Apnea

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

  • A heart-healthy diet
  • Weight loss if you are overweight
  • Not smoking (or quitting if you do smoke)
  • Sleeping on your side
  • Adequate, good-quality sleep
  • Limited alcohol and no sedatives
  • Good management of allergies
  • Improvements to nasal airflow
  • Stop mouth breathing (but not with oral tape)

Complications of Sleep Apnea

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

Undiagnosed sleep apnea can lead to chronic sleepiness in the daytime and problems with attention, memory issues, and irritability. It can also lead to relationship stress if loud snoring interferes with a partner’s sleep.

Over time, untreated sleep apnea may increase your risk of:

  • Metabolic syndrome
  • Heart disease
  • High blood pressure
  • Stroke
  • Type 2 diabetes
  • Glaucoma

  • Pregnancy complications (including gestational diabetes and hypertension)

  • Cancers (such as pancreatic, renal, or skin cancer)
  • Depression
And because sleep apnea can lead to sleepiness in the daytime, it can also increase your risk of accidents. A number of train crashes, road accidents, and other industrial accidents are suspected to have been caused by an operator falling asleep because of sleep apnea.

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 question of just how many people have sleep apnea is tricky: 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 even out when it comes to 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 affected 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) — 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 of 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 sleep apnea increases the likelihood of disorders such as cardiovascular disease (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 reciprocal link to sleep apnea: People who are overweight or obese are more likely to have sleep apnea, and people who have sleep apnea seem more susceptible to weight gain.

That two-way relationship can apply to weight loss, as well. Weight loss can improve sleep apnea by reducing the fatty deposits in the neck that 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 a loss of 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 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 more than three million participants 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.

The Takeaway

  • Sleep apnea is an extremely common disorder. Those who have it experience shallow or stopped breathing during sleep.
  • Certain chronic conditions such as obesity can increase the risk of sleep apnea.
  • If left untreated, sleep apnea can lead to serious complications, such as heart disease and diabetes.
  • Typical treatment options for sleep apnea include lifestyle changes or interventions such as medication, a CPAP machine, oral devices, surgery, or implants.

Common Questions & Answers

Can you die of 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.
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.
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.
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: weight loss, side sleeping, no alcohol late in the day, avoidance of certain drugs and medications, smoking cessation, and exercise.
Undiagnosed, untreated, or mismanaged sleep apnea can lead to chronic sleepiness in the daytime and to problems with memory, attention, irritability, and mood. The condition can also increase the risk of metabolic syndrome, heart disease, stroke, diabetes, glaucoma, pregnancy complications, accidents, and more.

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Alex Dimitriu, MD, is dual board-certified in psychiatry and sleep medicine. He helps his patients optimize peak performance by day and peak restorative sleep by night, and he brings a deep respect for science and spirituality into his work.

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