Accessible Search Form           Advanced Search


National Heart Lung and Blood Institute Logo

For more information, visit http://www.nhlbi.nih.gov/health/health-topics/topics/sleepapnea/


What Is Sleep Apnea?

Sleep apnea (AP-ne-ah) is a common disorder in which you have one or more pauses in breathing or shallow breaths while you sleep.

Breathing pauses can last from a few seconds to minutes. They may occur 30 times or more an hour. Typically, normal breathing then starts again, sometimes with a loud snort or choking sound.

Sleep apnea usually is a chronic (ongoing) condition that disrupts your sleep. When your breathing pauses or becomes shallow, you’ll often move out of deep sleep and into light sleep.

As a result, the quality of your sleep is poor, which makes you tired during the day. Sleep apnea is a leading cause of excessive daytime sleepiness.

Overview

Sleep apnea often goes undiagnosed. Doctors usually can't detect the condition during routine office visits. Also, no blood test can help diagnose the condition.

Most people who have sleep apnea don't know they have it because it only occurs during sleep. A family member or bed partner might be the first to notice signs of sleep apnea.

The most common type of sleep apnea is obstructive sleep apnea. In this condition, the airway collapses or becomes blocked during sleep. This causes shallow breathing or breathing pauses.

When you try to breathe, any air that squeezes past the blockage can cause loud snoring. Obstructive sleep apnea is more common in people who are overweight, but it can affect anyone. For example, small children who have enlarged tonsil tissues in their throats may have obstructive sleep apnea.

The animation below shows how obstructive sleep apnea occurs. Click the "start" button to play the animation. Written and spoken explanations are provided with each frame. Use the buttons in the lower right corner to pause, restart, or replay the animation, or use the scroll bar below the buttons to move through the frames.

The animation shows how the airway can collapse and block air flow to the lungs, causing sleep apnea.

Central sleep apnea is a less common type of sleep apnea. This disorder occurs if the area of your brain that controls your breathing doesn't send the correct signals to your breathing muscles. As a result, you'll make no effort to breathe for brief periods.

Central sleep apnea can affect anyone. However, it's more common in people who have certain medical conditions or use certain medicines.

Central sleep apnea can occur with obstructive sleep apnea or alone. Snoring typically doesn't happen with central sleep apnea.

This article mainly focuses on obstructive sleep apnea.

Outlook

Untreated sleep apnea can:

Sleep apnea is a chronic condition that requires long-term management. Lifestyle changes, mouthpieces, surgery, and breathing devices can successfully treat sleep apnea in many people.



Other Names for Sleep Apnea

  • Central sleep apnea
  • Obstructive sleep apnea
  • Sleep-disordered breathing


What Causes Sleep Apnea?

When you're awake, throat muscles help keep your airway stiff and open so air can flow into your lungs. When you sleep, these muscles relax, which narrows your throat.

Normally, this narrowing doesn’t prevent air from flowing into and out of your lungs. But if you have sleep apnea, your airway can become partially or fully blocked because:

  • Your throat muscles and tongue relax more than normal.
  • Your tongue and tonsils (tissue masses in the back of your mouth) are large compared with the opening into your windpipe.
  • You're overweight. The extra soft fat tissue can thicken the wall of the windpipe. This narrows the inside of the windpipe, which makes it harder to keep open.
  • The shape of your head and neck (bony structure) may cause a smaller airway size in the mouth and throat area.
  • The aging process limits your brain signals' ability to keep your throat muscles stiff during sleep. Thus, your airway is more likely to narrow or collapse.

Not enough air flows into your lungs if your airway is partially or fully blocked during sleep. As a result, loud snoring and a drop in your blood oxygen level can occur.

If the oxygen drops to a dangerous level, it triggers your brain to disturb your sleep. This helps tighten the upper airway muscles and open your windpipe. Normal breathing then starts again, often with a loud snort or choking sound.

Frequent drops in your blood oxygen level and reduced sleep quality can trigger the release of stress hormones. These hormones raise your heart rate and increase your risk for high blood pressure, heart attack, stroke, and arrhythmias (irregular heartbeats). The hormones also can raise your risk for, or worsen, heart failure.

Untreated sleep apnea also can lead to changes in how your body uses energy. These changes increase your risk for obesity and diabetes.



Who Is at Risk for Sleep Apnea?

Obstructive sleep apnea is a common condition. About half of the people who have this condition are overweight.

Men are more likely than women to have sleep apnea. Although the condition can occur at any age, the risk increases as you get older.  A family history of sleep apnea also increases your risk for the condition.

People who have small airways in their noses, throats, or mouths are more likely to have sleep apnea. Small airways might be due to the shape of these structures or allergies or other conditions that cause congestion.

Small children might have enlarged tonsil tissues in their throats. Enlarged tonsil tissues raise a child’s risk for sleep apnea. Overweight children also might be at increased risk for sleep apnea.

About half of the people who have sleep apnea also have high blood pressure. Sleep apnea also is linked to smoking, metabolic syndrome, diabetes, and risk factors for stroke and heart failure.

Race and ethnicity might play a role in the risk of developing sleep apnea. However, more research is needed.



What Are the Signs and Symptoms of Sleep Apnea?

Major Signs and Symptoms

One of the most common signs of obstructive sleep apnea is loud and chronic (ongoing) snoring. Pauses may occur in the snoring. Choking or gasping may follow the pauses.

The snoring usually is loudest when you sleep on your back; it might be less noisy when you turn on your side. You might not snore every night. Over time, however, the snoring can happen more often and get louder.

You're asleep when the snoring or gasping happens. You likely won't know that you're having problems breathing or be able to judge how severe the problem is. A family member or bed partner often will notice these problems before you do.

Not everyone who snores has sleep apnea.

Another common sign of sleep apnea is fighting sleepiness during the day, at work, or while driving. You may find yourself rapidly falling asleep during the quiet moments of the day when you're not active. Even if you don't have daytime sleepiness, talk with your doctor if you have problems breathing during sleep.

Other Signs and Symptoms

Others signs and symptoms of sleep apnea include:

  • Morning headaches
  • Memory or learning problems and not being able to concentrate
  • Feeling irritable, depressed, or having mood swings or personality changes
  • Waking up frequently to urinate
  • Dry mouth or sore throat when you wake up

In children, sleep apnea can cause hyperactivity, poor school performance, and angry or hostile behavior. Children who have sleep apnea also may breathe through their mouths instead of their noses during the day.



How Is Sleep Apnea Diagnosed?

Doctors diagnose sleep apnea based on medical and family histories, a physical exam, and sleep study results. Your primary care doctor may evaluate your symptoms first. He or she will then decide whether you need to see a sleep specialist.

Sleep specialists are doctors who diagnose and treat people who have sleep problems. Examples of such doctors include lung and nerve specialists and ear, nose, and throat specialists. Other types of doctors also can be sleep specialists.

Medical and Family Histories

If you think you have a sleep problem, consider keeping a sleep diary for 1 to 2 weeks. Bring the diary with you to your next medical appointment.

Write down when you go to sleep, wake up, and take naps. Also write down how much you sleep each night, how alert and rested you feel in the morning, and how sleepy you feel at various times during the day. This information can help your doctor figure out whether you have a sleep disorder.

You can find a sample sleep diary in the National Heart, Lung, and Blood Institute's "Your Guide to Healthy Sleep."

At your appointment, your doctor will ask you questions about how you sleep and how you function during the day.

Your doctor also will want to know how loudly and often you snore or make gasping or choking sounds during sleep. Often you're not aware of such symptoms and must ask a family member or bed partner to report them.

Let your doctor know if anyone in your family has been diagnosed with sleep apnea or has had symptoms of the disorder.

Many people aren't aware of their symptoms and aren't diagnosed.

If you're a parent of a child who may have sleep apnea, tell your child's doctor about your child's signs and symptoms.

Physical Exam

Your doctor will check your mouth, nose, and throat for extra or large tissues. Children who have sleep apnea might have enlarged tonsils. Doctors may need only a physical exam and medical history to diagnose sleep apnea in children.

Adults who have sleep apnea may have an enlarged uvula (U-vu-luh) or soft palate. The uvula is the tissue that hangs from the middle of the back of your mouth. The soft palate is the roof of your mouth in the back of your throat.

Sleep Studies

Sleep studies are tests that measure how well you sleep and how your body responds to sleep problems. These tests can help your doctor find out whether you have a sleep disorder and how severe it is. Sleep studies are the most accurate tests for diagnosing sleep apnea.

There are different kinds of sleep studies. If your doctor thinks you have sleep apnea, he or she may recommend a polysomnogram (poly-SOM-no-gram; also called a PSG) or a home-based portable monitor.

Polysomnogram

A PSG is the most common sleep study for diagnosing sleep apnea. This study records brain activity, eye movements, heart rate, and blood pressure.

A PSG also records the amount of oxygen in your blood, air movement through your nose while you breathe, snoring, and chest movements. The chest movements show whether you're making an effort to breathe.

PSGs often are done at sleep centers or sleep labs. The test is painless. You'll go to sleep as usual, except you'll have sensors attached to your scalp, face, chest, limbs, and a finger. The staff at the sleep center will use the sensors to check on you throughout the night.

A sleep specialist will review the results of your PSG to see whether you have sleep apnea and how severe it is. He or she will use the results to plan your treatment.

Your doctor also may use a PSG to find the best setting for you on a CPAP (continuous positive airway pressure) machine. CPAP is the most common treatment for sleep apnea. A CPAP machine uses mild air pressure to keep your airway open while you sleep.

If your doctor thinks that you have sleep apnea, he or she may schedule a split-night sleep study. During the first half of the night, your sleep will be checked without a CPAP machine. This will show whether you have sleep apnea and how severe it is.

If the PSG shows that you have sleep apnea, you’ll use a CPAP machine during the second half of the split-night study. The staff at the sleep center will adjust the flow of air from the CPAP machine to find the setting that works best for you.

Home-Based Portable Monitor

Your doctor may recommend a home-based sleep test with a portable monitor. The portable monitor will record some of the same information as a PSG. For example, it may record:

  • The amount of oxygen in your blood
  • Air movement through your nose while you breathe
  • Your heart rate
  • Chest movements that show whether you're making an effort to breathe

A sleep specialist may use the results from a home-based sleep test to help diagnose sleep apnea. He or she also may use the results to decide whether you need a full PSG study in a sleep center.



How Is Sleep Apnea Treated?

Sleep apnea is treated with lifestyle changes, mouthpieces, breathing devices, and surgery. Medicines typically aren't used to treat the condition.

The goals of treating sleep apnea are to:

  • Restore regular breathing during sleep
  • Relieve symptoms such as loud snoring and daytime sleepiness

Treatment may improve other medical problems linked to sleep apnea, such as high blood pressure. Treatment also can reduce your risk for heart disease, stroke, and diabetes.

If you have sleep apnea, talk with your doctor or sleep specialist about the treatment options that will work best for you.

Lifestyle changes and/or mouthpieces may relieve mild sleep apnea. People who have moderate or severe sleep apnea may need breathing devices or surgery.

If you continue to have daytime sleepiness despite treatment, your doctor may ask whether you're getting enough sleep. (Adults should get at least 7 to 8 hours of sleep; children and teens need more. For more information, go to the Health Topics Sleep Deprivation and Deficiency article.)

If treatment and enough sleep don't relieve your daytime sleepiness, your doctor will consider other treatment options.

Lifestyle Changes

If you have mild sleep apnea, some changes in daily activities or habits might be all the treatment you need.

  • Avoid alcohol and medicines that make you sleepy. They make it harder for your throat to stay open while you sleep.
  • Lose weight if you're overweight or obese. Even a little weight loss can improve your symptoms.
  • Sleep on your side instead of your back to help keep your throat open. You can sleep with special pillows or shirts that prevent you from sleeping on your back.
  • Keep your nasal passages open at night with nasal sprays or allergy medicines, if needed. Talk with your doctor about whether these treatments might help you.
  • If you smoke, quit. Talk with your doctor about programs and products that can help you quit smoking.

Mouthpieces

A mouthpiece, sometimes called an oral appliance, may help some people who have mild sleep apnea. Your doctor also may recommend a mouthpiece if you snore loudly but don't have sleep apnea.

A dentist or orthodontist can make a custom-fit plastic mouthpiece for treating sleep apnea. (An orthodontist specializes in correcting teeth or jaw problems.) The mouthpiece will adjust your lower jaw and your tongue to help keep your airways open while you sleep.

If you use a mouthpiece, tell your doctor if you have discomfort or pain while using the device. You may need periodic office visits so your doctor can adjust your mouthpiece to fit better.

Breathing Devices

CPAP (continuous positive airway pressure) is the most common treatment for moderate to severe sleep apnea in adults. A CPAP machine uses a mask that fits over your mouth and nose, or just over your nose.

The machine gently blows air into your throat. The pressure from the air helps keep your airway open while you sleep.

Treating sleep apnea may help you stop snoring. But not snoring doesn't mean that you no longer have sleep apnea or can stop using CPAP. Your sleep apnea will return if you stop using your CPAP machine or don’t use it correctly.

Usually, a technician will come to your home to bring the CPAP equipment. The technician will set up the CPAP machine and adjust it based on your doctor's prescription. After the initial setup, you may need to have the CPAP adjusted from time to time for the best results.

CPAP treatment may cause side effects in some people. These side effects include a dry or stuffy nose, irritated skin on your face, dry mouth, and headaches. If your CPAP isn't adjusted properly, you may get stomach bloating and discomfort while wearing the mask.

If you're having trouble with CPAP side effects, work with your sleep specialist, his or her nursing staff, and the CPAP technician. Together, you can take steps to reduce the side effects.

For example, the CPAP settings or size/fit of the mask might need to be adjusted. Adding moisture to the air as it flows through the mask or using nasal spray can help relieve a dry, stuffy, or runny nose.

There are many types of CPAP machines and masks. Tell your doctor if you're not happy with the type you're using. He or she may suggest switching to a different type that might work better for you.

People who have severe sleep apnea symptoms generally feel much better once they begin treatment with CPAP.

Surgery

Some people who have sleep apnea might benefit from surgery. The type of surgery and how well it works depend on the cause of the sleep apnea.

Surgery is done to widen breathing passages. It usually involves shrinking, stiffening, or removing excess tissue in the mouth and throat or resetting the lower jaw.

Surgery to shrink or stiffen excess tissue is done in a doctor's office or a hospital. Shrinking tissue may involve small shots or other treatments to the tissue. You may need a series of treatments to shrink the excess tissue. To stiffen excess tissue, the doctor makes a small cut in the tissue and inserts a piece of stiff plastic.

Surgery to remove excess tissue is done in a hospital. You're given medicine to help you sleep during the surgery. After surgery, you may have throat pain that lasts for 1 to 2 weeks.

Surgery to remove the tonsils, if they're blocking the airway, might be helpful for some children. Your child's doctor may suggest waiting some time to see whether these tissues shrink on their own. This is common as small children grow.



Living With Sleep Apnea

Sleep apnea can be very serious. However, following an effective treatment plan often can improve your quality of life quite a bit.

Treatment can improve your sleep and relieve daytime sleepiness. Treatment also might lower your risk for high blood pressure, heart disease, and other health problems linked to sleep apnea.

Treatment may improve your overall health and happiness as well as your quality of sleep (and possibly your family's quality of sleep).

Ongoing Health Care Needs

Follow up with your doctor regularly to make sure your treatment is working. Tell him or her if the treatment is causing bothersome side effects.

Ongoing care is important if you're getting CPAP (continuous positive airway pressure) treatment. It may take a while before you adjust to using CPAP.

If you aren't comfortable with your CPAP device, or if it doesn't seem to be working, let your doctor know. You may need to switch to a different device or mask. Or, you may need treatment to relieve CPAP side effects.

Try not to gain weight. Weight gain can worsen sleep apnea and require adjustments to your CPAP device. In contrast, weight loss may relieve your sleep apnea.

Until your sleep apnea is properly treated, know the dangers of driving or operating heavy machinery while sleepy.

If you're having any type of surgery that requires medicine to put you to sleep, let your surgeon and doctors know you have sleep apnea. They might have to take extra steps to make sure your airway stays open during the surgery.

If you're using a mouthpiece to treat your sleep apnea, you may need to have routine checkups with your dentist.

How Can Family Members Help?

Often, people who have sleep apnea don't know they have it. They're not aware that their breathing stops and starts many times while they're sleeping. Family members or bed partners usually are the first to notice signs of sleep apnea.

Family members can do many things to help a loved one who has sleep apnea.

  • Let the person know if he or she snores loudly during sleep or has breathing stops and starts.
  • Encourage the person to get medical help.
  • Help the person follow the doctor's treatment plan, including CPAP treatment.
  • Provide emotional support.


Clinical Trials

The National Heart, Lung, and Blood Institute (NHLBI) is strongly committed to supporting research aimed at preventing and treating heart, lung, and blood diseases and conditions and sleep disorders.

NHLBI-supported research has led to many advances in medical knowledge and care. For example, this research has uncovered some of the causes of various sleep disorders and ways to diagnose and treat them.

The NHLBI continues to support research to learn more about sleep and sleep disorders. For example, the NHLBI’s Sleep Heart Health Study showed that moderate to severe sleep apnea is associated with an increased risk of stroke and death in middle-aged adults, especially men. Current NHLBI studies are exploring:

  • How obesity and sleep apnea affect inflammation and heart disease
  • Whether CPAP treatment affects how the body uses glucose (sugar)
  • New behavioral programs and methods to help patients adhere to CPAP treatment

In November 2011, the National Institutes of Health (NIH) released its "2011 NIH Sleep Disorders Research Plan." The plan expands upon previous and current research programs and identifies new research opportunities.

The NHLBI's National Center on Sleep Disorders Research coordinates this research across the NIH and other Federal agencies. The research focuses on sleep and the body's natural 24-hour cycle, the role of genes and the environment on sleep health, and ways to improve the prevention, diagnosis, and treatment of sleep disorders.

Much of this research depends on the willingness of volunteers to take part in clinical trials. Clinical trials test new ways to prevent, diagnose, or treat various diseases, conditions, and health problems.

For example, new treatments for a disease or condition (such as medicines, medical devices, surgeries, or procedures) are tested in volunteers who have the illness. Testing shows whether a treatment is safe and effective in humans before it is made available for widespread use.

By taking part in a clinical trial, you may gain access to new treatments before they're widely available. You also will have the support of a team of health care providers, who will likely monitor your health closely. Even if you don't directly benefit from the results of a clinical trial, the information gathered can help others and add to scientific knowledge.

If you volunteer for a clinical trial, the research will be explained to you in detail. You'll learn about treatments and tests you may receive, and the benefits and risks they may pose. You'll also be given a chance to ask questions about the research. This process is called informed consent.

If you agree to take part in the trial, you'll be asked to sign an informed consent form. This form is not a contract. You have the right to withdraw from a study at any time, for any reason. Also, you have the right to learn about new risks or findings that emerge during the trial.

For more information about clinical trials related to sleep apnea, talk with your doctor. You also can visit the following Web sites to learn more about clinical research and to search for clinical trials:

For more information about clinical trials for children, visit the NHLBI's Children and Clinical Studies Web page.



Links to Other Information About Sleep Apnea

NHLBI Resources

Non-NHLBI Resources

Clinical Trials

 
July 10, 2012 Last Updated Icon

The NHLBI updates Health Topics articles on a biennial cycle based on a thorough review of research findings and new literature. The articles also are updated as needed if important new research is published. The date on each Health Topics article reflects when the content was originally posted or last revised.
Twitter iconTwitter         Facebook iconFacebook         YouTube iconYouTube