Sleep Apnea

Obesity is a common cause of sleep apnea in adults. People with this condition have increased fat deposits in their necks that can block the upper airway.

Large tonsils may contribute to sleep apnea, because they narrow the upper airway.

The endocrine system produces hormone that can affect sleep-related breathing. The following are examples of endocrine disorders associated with sleep apnea:

• Hypothyroidism: People with this condition have low levels of thyroid hormones. This affects the part of the brain that controls breathing, as well as the nerves and muscles used to breathe. People with hypothyroidism can also be diagnosed with obesity, which can cause sleep apnea.
• Acromegaly: People with this condition have high levels of growth hormone. This condition is associated with changes in the facial bones, swelling of the throat, and an increased size of the tongue. These changes can obstruct the upper airway and lead to sleep apnea.
• Polycystic ovary syndrome (PCOS): Sleep apnea is also seen in women with PCOS, an endocrine condition that causes large ovaries and prevents proper ovulation. PCOS is also associated with overweight and obesity, which can cause sleep apnea.

Conditions interfering with brain signals to airway and chest muscles can cause sleep apnea. Some of these conditions are stroke, amyotrophic lateral sclerosis, Chiari malformations, myotonic dystrophy, post-polio syndrome, dermatomyositis, myasthenia gravis, and Lambert-Eaton myasthenic syndrome.

Sleep apnea is commonly found in people who have advanced heart or kidney failure. These patients may have fluid build-up in their neck, which can obstruct the upper airway and cause sleep apnea.

Genetic syndromes that affect the structure of the face or skull, particularly syndromes that cause smaller facial bones or cause the tongue to sit farther back in the mouth, may cause sleep apnea. These genetic syndromes include cleft lip and cleft palate, Down syndrome and congenital central hypoventilation syndrome.

Babies born before 37 weeks of pregnancy have a higher risk for breathing problems during sleep. In most cases, the risk decreases as the brain matures.

Sleep apnea can occur at any age. The risk for sleep apnea increases as you get older. In younger adults, sleep apnea is more common in men than in women, but the difference decreases later in life. Normal age-related changes in how the brain controls breathing during sleep partially explain the increased risk as you get older. Another possible reason is that as we age, more fatty tissue builds up in the neck and the tongue.

Drinking alcohol, smoking, and overweight or obesity can increase your risk for sleep apnea.

• Alcohol can increase relaxation of the muscles in the mouth and throat, closing the upper airway. It can also affect how the brain controls sleep or the muscles involved in breathing.
• Smoking can cause inflammation in the upper airway, affecting breathing, or it can affect how the brain controls sleep or the muscles involved in breathing.
• Unhealthy eating patterns and lack of physical activity can lead to overweight and obesity, which can result in sleep apnea.

Researchers have identified family history as a risk factor for sleep apnea, but maintaining a healthy lifestyle can decrease this risk. Studies in twins have shown that sleep apnea can be inherited. Some of the gene related to sleep apnea are associated with the structural development of the face and skull and with how the brain controls sleep and breathing during sleep. Some genes are also associated with obesity and inflammation.

In the United States, sleep apnea is more common among blacks, Hispanics, and Native Americans than among whites.

To screen for sleep apnea or other sleep disorders, your doctor may ask you about common signs and symptoms of this condition, such as how sleepy you feel during the day or when driving, and whether you or your partner has noticed that you snore, stop breathing, or gasp during your sleep. Your doctor may ask questions to assess your risk for developing this condition and take your physical measurements. Your doctor will also want to see whether you have any complications of undiagnosed sleep apnea, such as high blood pressure that is difficult to control. If the screening suggests a sleep breathing disorder, you may get a referral to a sleep specialist to help confirm a diagnosis.

If you are concerned about having risk factors for developing sleep apnea, ask your doctor to recommend healthy lifestyle changes, including eating a heart-healthy diet, aiming for a healthy weight, quitting smoking, and limiting alcohol intake. Your doctor may recommend that you sleep on your side and adopt healthy sleep habits such as getting the recommended amount of sleep.

• Diagnosis will discuss tests and procedures that your doctor may use to diagnose sleep apnea and rule out other conditions or medicines that may be causing symptoms of sleep apnea.
• Living With will explain what your doctor may recommend to prevent your sleep apnea from recurring, getting worse, or causing complications.
• Research for Your Health will discuss how we are using current research and advancing research to prevent sleep apnea.
• Participate in NHLBI Clinical Trials will explain our ongoing clinical trials that are investigating prevention strategies for sleep apnea.

Common sign of sleep apnea:

• Reduced or absent breathing, known as apnea events
• Frequent loud snoring
• Gasping for air during sleep

Common symptom of sleep apnea:

• Excessive daytime sleepiness and fatigue
• Decreases in attention, vigilance, concentration, motor skills, and verbal and visuospatial memory
• Dry mouth or headaches when waking
• Sexual dysfunction or decreased libido
• Waking up often during the night to urinate

Did you know that sleep apnea symptoms may be different for women and children compared with men?

Sleep apnea may increase your risk of the following disorders:

• Asthma
• Atrial fibrillation
• Cancers, such as pancreatic, renal, and skin cancers
• Chronic kidney disease
• Cognitive and behavioral disorders, such as decreases in attention, vigilance, concentration, motor skills, and verbal and visuospatial memory, as well as dementia in older adults. In children, sleep apnea has been associated with learning disabilities.
• Diseases of the heart and blood vessels, such as atherosclerosis, heart attacks, heart failure, difficult-to-control high blood pressure, and stroke
• Eye disorders, such as glaucoma, dry eye, or keratoconus
• Metabolic disorders, including glucose intolerance and type 2 diabetes
• Pregnancy complications, including gestational diabetes and gestational high blood pressure, as well as having a baby with low birth weight

Did you know that sleep apnea can cause inflammation and lead to complications?

• Diagnosis will explain tests and procedures used to detect signs of sleep apnea and help rule our other conditions that may resemble sleep apnea.
• Treatment will discuss treatment-related complications or side effects of the treatment for sleep apnea.

To help diagnose sleep apnea, your doctor may consider the following:

• Information that you provide, such as signs and symptoms that you are experiencing
• Whether you have a family history of sleep apnea or another sleep disorder
• Whether you have risk factors for sleep apnea
• Whether you have complications of undiagnosed or untreated sleep apnea, such as atrial fibrillation, type 2 diabetes, or hard-to-control high blood pressure

During the physical exam, your doctor will look for signs of other conditions that can increase your risk for sleep apnea, such as obesity, large tonsils, narrowing of the upper airway, or a large neck circumference. A neck circumference greater than 17 inches for men or 16 inches for women is considered large. Your doctor may also look at your jaw size and structure, the size of your tongue, and your tongue’s position in your mouth. Your doctor will check your lungs, heart, and neurological systems to see whether you have any common complications of sleep apnea.

To diagnose sleep apnea or another sleep disorder, your doctor may refer you to a sleep specialist or a center for a sleep study. Sleep studies can be done in a special center or at home. Studies at a sleep center can:

• Detect apnea events, which are times when your breathing stops or slows during sleep
• Detect low or high levels of activity in muscles that control breathing
• Monitor blood oxygen levels during sleep
• Monitor brain and heart activity during sleep

Your doctor may be able to diagnose mild, moderate, or severe sleep apnea based on the number of sleep apnea events you have in an hour during the sleep study.

• Mild: Five to 14 apnea events in an hour
• Moderate: 15 to 29 apnea events in an hour
• Severe: 30 or more apnea events in an hour

Visit Sleep Studies for more information.

Did you know that sleep studies can help determine which type of sleep apnea you have?

Your doctor may order the following tests to help rule out other medical conditions that can cause sleep apnea:

• Blood tests to check the levels of certain hormones and to rule out endocrine disorders that could be contributing to sleep apnea. Thyroid hormone can rule out hypothyroidism. Growth hormone tests can rule out acromegaly. Total testosterone and dehydroepiandrosterone sulphate (DHEAS) tests can help rule out polycystic ovary syndrome (PCOS).
• Pelvic ultrasound to examine the ovaries and detect cysts. This can rule out PCOS.

Your doctor will also want to know whether you are using medicines, such as opioids, that could be affecting your sleep or causing breathing symptoms of sleep apnea. Your doctor may want to know whether you have traveled recently to altitudes greater than 6,000 feet, because these low-oxygen environments can cause symptoms of sleep apnea for a few weeks after traveling.

• Return to Risk Factors to review family history, lifestyle, or other environmental factors that increase your risk of developing sleep apnea.
• Return to Signs, Symptoms, and Complications to review common symptoms of sleep apnea.
• Return to Screening and Prevention to review how to screen for and prevent sleep apnea.

To help control or treat your sleep apnea, your doctor may recommend that you adopt lifelong healthy lifestyle changes.

• Make heart-healthy eating choices. This also includes limiting your alcohol intake, especially before bedtime.
• Get regular physical activity.
• Aim for a healthy weight. Research has shown that losing weight can reduce sleep apnea in people who were also diagnosed with obesity.
• Develop healthy sleeping habits. Your doctor may recommend general healthy sleep habits, which include getting the recommended amount of sleep based on your age.
• Quit smoking. Visit Smoking and Your Heart and the National Heart, Lung, and Blood Institute’s Your Guide to a Healthy Heart [PDF 2.9MB]. Although these resources focus on heart health, they include basic information about how to quit smoking. For free help and support to quit smoking, call the National Cancer Institute’s Smoking Quitline at 1-877-44U-QUIT (1-877-448-7848).

A breathing device, such as a CPAP machine, is the most commonly recommended treatment for patients with sleep apnea. If your doctor prescribes a CPAP or other breathing device, be sure to continue your doctor-recommended healthy lifestyle changes. Read Living With to learn more about properly caring for your breathing device.

Mouthpieces, or oral appliances, are typically custom-fit devices that you wear while you sleep. There are two types of mouthpieces that work differently to open the upper airway. Some hybrid mouthpieces have features of both types.

• Mandibular repositioning mouthpieces are devices that cover the upper and lower teeth and hold the jaw in a position that prevents it from blocking the upper airway.
• Tongue retaining devices are mouthpieces that hold the tongue in a forward position to prevent it from blocking the upper airway.

Your doctor may prescribe a mouthpiece if you have mild sleep apnea or if your apnea occurs only when you are lying on your back. To get your mouthpiece, your doctor may recommend that you visit a dentist or an orthodontist, a type of dentist who specializes in correcting teeth or jaw problems. These specialists will ensure that the oral appliance is custom fit to your mouth and jaw.

Implants can benefit some people with sleep apnea. Some devices treat both obstructive and central sleep apnea. You must have surgery to place an implant in your body. The Food and Drug Administration has approved one implant as a treatment for sleep apnea. The device senses breathing patterns and delivers mild stimulation to certain muscles that open the airways during sleep. More research is needed to determine how effective the implant is in treating central sleep apnea.

A nerve stimulator can also treat sleep apnea. This treatment also involves surgery. A surgeon will insert a stimulator for the hypoglossal nerve, which controls tongue movement. Increasing stimulation of this nerve helps position the tongue to keep the upper airway open.

Children and adults with sleep apnea may benefit from therapy for mouth and facial muscles, known as orofacial therapy. This therapy helps improve tongue positioning and strengthen muscles that control the lips, tongue, soft palate, lateral pharyngeal wall, and face.

You may need surgery if you have severe obstructive sleep apnea that does not respond to breathing devices such as a CPAP machine, or that is caused by visible obstruction to the upper airway, perhaps due to large tonsils. Possible surgical procedures include:

• Tonsillectomy: a surgery to remove the tonsils, which are organs at the back of your throat
• Maxillary or jaw advancement: a surgery to move the upper jaw (maxilla) and lower jaw (mandible) forward, to enlarge the upper airway
• Tracheostomy: a surgery to make a hole through the front of your neck into your trachea, or windpipe. A breathing tube, called a trach tube, is placed through the hole and directly into your windpipe to help you breathe.

If surgery is considered as a possible treatment, talk to your doctor about the different types of surgical procedures, the risks and benefits of the procedures, potential discomfort, and the recovery time you will need after surgery.

• Living With will explain what your doctor may recommend, including lifelong lifestyle changes and medical care to prevent your condition from recurring, getting worse, or causing complications.
• Research for Your Health will discuss how we are using current research and advancing research to treat people with sleep apnea.
• Participate in NHLBI Clinical Trials will discuss our ongoing clinical studies that are investigating treatments for sleep apnea.

It is important that you properly use and care for your prescribed breathing device or mouthpiece. If your doctor prescribed a breathing device or CPAP machine:

• Be patient with your breathing device or CPAP machine. It may take time to adjust to breathing with the help of a CPAP machine.
• Use your breathing device or CPAP machine for all sleep, including naps. To benefit fully from your treatment, you should wear your device whenever and wherever you sleep. If you are traveling, be sure to bring your breathing device with you. Call your doctor or sleep specialist right away if your device stops working correctly.
• Talk to your doctor or supplier if you experience discomfort or have difficulty using your prescribed breathing device. Let the team or supplier know if you are having irritation from the mask, if your mask is not staying on or fitting well, if it leaks air, if you are having difficulty falling or staying asleep, if you wake with dry mouth, or if you have a stuffy or runny nose. Your doctor can explore options to improve the treatment, such as trying different masks or nasal pillows, adjusting the machine’s pressure timing and settings, or trying a different breathing device that has a humidifier chamber or provides bi-level or auto-adjusting pressure settings. Cleaning the mask and washing your face before putting your mask on can help make a better seal between the mask and your skin.
• Properly care for your breathing device or CPAP machine. Know how to set up and properly clean all parts of your machine. Be sure to refill prescriptions on time for all of the device’s replaceable parts, including the tubes, masks, and air filters.
• Properly care for your mouthpiece. If you were prescribed a mouthpiece, ask your dentist how to properly care for it. If it does not fit right or your signs and symptoms do not improve, let your dentist know so that he or she can adjust the device. It is common to feel some discomfort after a device is adjusted until your mouth and facial muscles get used to the new fit.

You should visit your doctor to monitor your response to treatment and see whether you have any complications that, if left untreated, can be life-threatening. Your doctor may do any of the following to monitor your condition.

• If your doctor prescribed a breathing device, your doctor and possibly your insurance company will want to check the data card from the machine. The data card shows how often you use the breathing device and whether the device and its pressure settings are helping to reduce or eliminate apnea events while you sleep. Your doctor may also check to see whether you still experience excessive sleepiness during the day, how you feel about your quality of life, whether you are still snoring, or whether have experienced weight loss or changes in your lifestyle.
• If you were prescribed a mouthpiece, you should follow up with your dental specialist after six months and then at least every year. This is to see whether the mouthpiece is working correctly, whether it needs adjustment, and whether a replacement device is needed.

Sometimes, repeat sleep studies are necessary. Your doctor may have you repeat a sleep study to monitor your response to the treatment, especially if your sleep symptoms continue, if you are using a mouthpiece, if your weight changes significantly, or if your employer requires these tests.

Side effects of CPAP treatment may include congestion, runny nose, dry mouth, dry eyes, or nosebleeds. If you experience stomach discomfort or bloating, you should stop using your CPAP machine and contact your doctor.

Sleep apnea can increase your risks of complications if you are having surgery, and it can affect your ability to drive.

• Before surgery. If you are having any type of surgery that requires medicine to put you to sleep or for pain management, let your surgeon and doctors know that you have sleep apnea. They might have to take extra steps to make sure that your upper airway stays open during the surgery and when selecting your pain medicines.
• Driving precautions. Undiagnosed and untreated sleep apnea can decrease learning capabilities, slow down decision making, and decrease attention span, which can result in drowsy driving.