What Is Sleep Apnea?

Sleep disorders are a disruption in an individual’s sleep quality, timing and duration of sleep hours. These sleep pattern conditions negatively affect overall health. Examples of sleep disorders are insomnia, narcolepsy, restless leg syndrome (RLS) and sleep apnea. 

Sleep apnea is a common sleep disorder characterized by brief interruptions of breathing during sleep. These episodes usually last 10 seconds or more and occur repeatedly throughout the night. People with sleep apnea will partially awaken as they struggle to breathe, but they will not be aware of the disturbances in their sleep when they wake up in the morning.

Snoring may be more than just an annoying habit—it may be a sign of sleep apnea. Persons with sleep apnea characteristically make periodic gasping or “snorting” noises, during which their sleep is momentarily interrupted. Those with sleep apnea may also experience excessive daytime sleepiness, as their sleep is commonly interrupted and may not feel restorative. Treatment of sleep apnea is dependent on its cause. If other medical problems are present, such as congestive heart failure or nasal obstruction, sleep apnea may resolve with treatment of these conditions. Gentle air pressure administered during sleep (typically in the form of a nasal continuous positive airway pressure device) may also be effective in the treatment of sleep apnea. As interruption of regular breathing or obstruction of the airway during sleep can pose serious health complications, symptoms of sleep apnea should be taken seriously. Treatment should be sought from a healthcare provider.

Types of Sleep Apnea

The most common type of sleep apnea is obstructive sleep apnea (OSA), which is caused by relaxation of soft tissue in the back of the throat that blocks the passage of air.

Central sleep apnea (CSA) is caused by irregularities in the brain’s signals to breathe.

Most people with sleep apnea will have a combination of both types. The hallmark symptom of the disorder is excessive daytime sleepiness. Additional symptoms of sleep apnea include:

  • Restless sleep
  • Loud snoring with periods of silence followed by gasps
  • Falling asleep during the day
  • Morning headaches
  • Trouble concentrating
  • Irritability
  • Forgetfulness
  • Mood or behavior changes
  • Anxiety
  • Depression

Not everyone who has these symptoms will have sleep apnea, but a visit to the doctor is recommended for people experiencing even a few.

Causes of Sleep Apnea

Sleep disorders are often the side effects of medications, substance abuse, depression or other previously undetected illness, such as heart disease, lung disease, nerve disorders and general pain. They are also linked to medical conditions, genetics, aging, diet and an irregular schedule.

As chronic diseases have assumed an increasingly common role in premature death and illness, interest in the role of sleep health in the development and management of chronic diseases has grown. Notably, insufficient sleep has been linked to the development and management of a number of chronic diseases and conditions, including type 2 diabetes, cardiovascular disease, obesity and depression.

The most common type of sleep apnea is obstructive sleep apnea (OSA), which is caused by conditions that block airflow through your upper airways during sleep. For example, relaxation of soft tissue in the back of the throat, including the tongue, that blocks the passage of air.

Central sleep apnea (CSA) is caused by irregularities in the brain’s signals to breathe.

Most people with sleep apnea will have a combination of both types. The hallmark symptom of the disorder is excessive daytime sleepiness. Additional symptoms of sleep apnea include:

  • Restless sleep
  • Loud snoring with periods of silence followed by gasps
  • Falling asleep during the day
  • Morning headaches
  • Trouble concentrating
  • Irritability
  • Forgetfulness
  • Mood or behavior changes
  • Anxiety
  • Depression

Risk Factors for Sleep Apnea

Many conditions can cause sleep apnea. Some factors, such as unhealthy lifestyle habits, can be changed. Other factors, such as age, family history, race and ethnicity, and sex, cannot be changed.

  • Age: As you get older, normal changes in how your brain controls breathing during sleep may raise your risk of sleep apnea.
  • Family history and genetics: Your genes can affect how your brain controls your breathing during sleep. Genetic conditions such as congenital central hypoventilation syndrome can raise your risk.
  • Lifestyle habits: Drinking alcohol and smoking can affect how your brain controls sleep or the muscles involved in breathing.
  • Opioid use: Opioid use disorder or long-term use of prescribed opioid-based pain medicines can cause problems with how your brain controls sleep.
  • Health conditions: Some conditions that affect how your brain controls your airway and chest muscles can raise your risk. These include heart failure, stroke, amyotrophic lateral sclerosis (ALS) and myasthenia gravis. Also, your hormone levels can affect how your brain controls your breathing.
  • Premature birth: Babies born before 37 weeks of pregnancy have a higher risk of breathing problems during sleep. In most cases, the risk gets lower as the baby gets older.

Screening for & Preventing Sleep Apnea

Screening for sleep disorders such as sleep apnea involves participating in a sleep study using surveillance systems to monitor sleep duration and quality. Additionally, a sleep diary can help you keep track of how long and how well you sleep, and how sleepy you feel during the day. These details can help your healthcare provider diagnose your condition.

You might also complete a questionnaire that asks the following questions:

  • On average, how many hours of sleep do you get in a 24-hour period?
  • Over the past two weeks, how many days have you had trouble falling asleep or staying asleep? 
  • Over the past two weeks, how many days did you unintentionally fall asleep during the day?
  • Have you ever been told that you snore loudly?
  • Has anyone ever observed that you stop breathing during your sleep?

You may be able to prevent obstructive sleep apnea by making healthy lifestyle changes, such as eating a heart-healthy diet, aiming for a healthy weight, quitting smoking and limiting alcohol intake. Your healthcare provider also may ask you to sleep on your side and to adopt healthy sleep habits such as getting the recommended amount of sleep.

Signs & Symptoms of Sleep Apnea

Signs of sleep disorders are disrupted sleep, an irregular wake cycle and general sleep challenges (falling asleep and staying asleep). Sleep-disordered individuals appear sleepy and unrested during the day.

Snoring may be more than just an annoying habit—it may be a sign of sleep apnea. Persons with sleep apnea characteristically make periodic gasping or “snorting” noises, during which their sleep is momentarily interrupted. Those with sleep apnea may also experience excessive daytime sleepiness, as their sleep is commonly interrupted and may not feel restorative.

The hallmark symptom of the disorder is excessive daytime sleepiness. Your partner may alert you to some of the symptoms of sleep apnea, such as:

  • Breathing that starts and stops during sleep
  • Frequent loud snoring with periods of silence followed by gasps
  • Gasping for air during sleep
  • Restless sleep
  • Falling asleep during the day
  • Morning headaches
  • Trouble concentrating
  • Irritability
  • Forgetfulness
  • Mood or behavior changes
  • Anxiety
  • Depression

You may also notice the following symptoms yourself:

  • Daytime sleepiness and tiredness, which can lead to problems learning, focusing and reacting
  • Dry mouth or headaches
  • Sexual dysfunction or decreased libido
  • Waking up often during the night to urinate

Children who have sleep apnea may be overactive and may experience bedwetting, worsening asthma and trouble paying attention in school. Talk to your healthcare provider about your symptoms. You may need a sleep study to help diagnose the condition.

Not everyone who has these symptoms will have sleep apnea, but a visit to the doctor is recommended for people experiencing even a few. Sleep apnea is more likely to occur in males than females, and in people who are overweight or obese.

Diagnosing Sleep Apnea

In addition to conducting a physical exam, your physician will review your medical and sleep histories. You might also complete a questionnaire that asks the following questions:

  • On average, how many hours of sleep do you get in a 24-hour period?
  • Over the past two weeks, how many days have you had trouble falling asleep or staying asleep? 
  • Over the past two weeks, how many days did you unintentionally fall asleep during the day?
  • Have you ever been told that you snore loudly?
  • Has anyone ever observed that you stop breathing during your sleep?

Screening for sleep disorders such as sleep apnea involves participating in a sleep study using surveillance systems to monitor sleep duration and quality. By using electrodes connected to your body, sleep studies monitor your whole system during a full night’s sleep, collecting the following data:

  • Breathing rate
  • Blood pressure
  • Heart rate
  • Changes in brain waves
  • Eye movements
  • Electrical activity of the heart and muscles

Your provider may order other tests to help rule out other medical conditions that can cause sleep apnea.

  • Blood tests that check the levels of certain hormones to check for endocrine disorders that could contribute to sleep apnea. Thyroid hormone tests 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 ultrasounds that examine the ovaries and help detect cysts. This can rule out PCOS.

Your provider will also want to know whether you are using medicines, such as opioids, that could affect your sleep or cause breathing symptoms of sleep apnea. They 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.

Treating Sleep Apnea

If a sleep study shows that you have sleep apnea, your healthcare provider may talk to you about making lifelong heart-healthy lifestyle changes. You may also need breathing or oral devices or surgery to help keep your airways open while you sleep.

To help treat your sleep apnea, you may need to adopt lifelong healthy lifestyle changes, which include getting regular physical activity, maintaining healthy sleeping habits and a healthy weight, limiting alcohol and quitting smoking. Your provider also may ask you to sleep on your side and not on your back. This helps keep your airway open while you sleep.

A breathing device, such as a CPAP machine, is the most common treatment for sleep apnea. A CPAP machine provides constant air pressure in your throat to keep the airway open when you breathe in. Breathing devices work best when you also make healthy lifestyle changes. Side effects of CPAP treatment may include:

  • Congestion
  • Dry eyes
  • Dry mouth
  • Nosebleeds
  • Runny nose

If you experience stomach discomfort or bloating, you should stop using your CPAP machine and contact your healthcare provider.

Depending on the type of sleep apnea you have, you may need another type of breathing device such as an auto-adjusting positive airway pressure (APAP) machine or a bilevel positive airway pressure (BPAP) machine. 

Oral devices, also called oral appliances, are custom-fit devices that you typically wear in your mouth while you sleep. There are two types of oral devices that work differently to open the upper airway while you sleep. Some hybrid devices 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.

A new type of oral device was recently approved by the FDA for use while awake. The device delivers electrical muscle stimulation through a removable mouthpiece that sits around the tongue. You wear the mouthpiece once a day for 20 minutes at a time, for six weeks. The device stimulates the tongue muscle while awake to help prevent the tongue from collapsing backward and blocking the airway during sleep.

If you have sleep apnea, your provider may prescribe an oral device if you do not want to use CPAP or cannot tolerate CPAP. They will recommend that you visit a dentist who will custom make an appliance for you, make sure that it is comfortable, and teach you how to use it to get the best results.

Additionally, exercises for your mouth and facial muscles, also called orofacial therapy, may help treat sleep apnea in children and adults. This therapy helps improve the position of your tongue and strengthens the muscles that control your lips, tongue, upper airway and face.

You may need surgery if other treatments do not work for you. Possible surgical procedures include:

  • Adenotonsillectomy to remove your tonsils and adenoids
  • Surgery to place an implant that monitors your breathing patterns and helps control certain muscles that open your airways during sleep
  • Surgery to remove some soft tissue from your mouth and throat, which helps make your upper airway bigger
  • Maxillary or jaw advancement surgery to move your upper jaw (maxilla) and lower jaw (mandible) forward, which helps make your upper airway bigger

Living with Sleep Apnea

If you have been diagnosed with sleep apnea, you will need to schedule regular checkups to make sure that your treatment is working and whether you have any complications. You may need to repeat your sleep study to monitor your symptoms while using your treatment, especially if you gain or lose a lot of weight. You may also need treatment for other health conditions that caused your sleep apnea or can make it worse.

Undiagnosed or untreated sleep apnea prevents you from getting enough rest, which can cause problems concentrating, remembering things, making decisions or controlling your behavior, as well as dementia in older adults. In children, sleep apnea can lead to problems with learning and memory, known as learning disabilities. The daytime sleepiness and fatigue that results from sleep apnea can also affect your child’s behavior and their desire to be physically active.

Sleep apnea affects many parts of your body. It can cause low oxygen levels in your body during sleep and can prevent you from getting enough good quality sleep. Also, it takes a lot of effort for you to restart breathing many times during sleep, and this can damage your organs and blood vessels. These factors may raise your risk of the following conditions:

  • Asthma
  • Cancers, such as pancreatic, renal and skin cancers
  • Chronic kidney disease
  • Eye problems, such a glaucoma, dry eye or an eye condition called keratoconus
  • Heart and blood vessel diseases, such as atrial fibrillation, atherosclerosis, difficult-to-control high blood pressure, heart attacks, heart failure, pulmonary hypertension and stroke
  • Metabolic syndrome
  • Pregnancy complications
  • Type 2 diabetes

Using & Caring for Your Breathing Device

It is important that you properly use and care for your breathing device.

  • Be patient as you learn to use your breathing device. It may take time to adjust to breathing with the help of a CPAP machine.
  • Use your breathing device for all sleep, including naps. If you are traveling, be sure to bring your breathing device with you.
  • Talk to your healthcare provider if the mask of your breathing device is not comfortable, if your mask is not staying on or fitting well, or if it leaks air. Also, tell your provider if you are having difficulty falling or staying asleep, if you wake up with dry mouth, or if you have a stuffy or runny nose. Your provider may ask you to try different masks or nasal pillows, or to adjust the machine’s pressure timing and settings.
  • Clean your mask and wash your face before you put on your mask. This can help make a better seal between the mask and your skin. You may need to try a different breathing device that has a humidifier chamber or provides bi-level or auto-adjusting pressure settings.
  • 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 parts that need to be replaced regularly, including the tubes, masks and air filters.

Your healthcare provider, and possibly your insurance provider, may ask to check the data card from your breathing device. This card shows how often you use your device and whether the device is working properly.

Using & Caring for Your Oral Device

If you are using an oral device, you may need to see your dentist after six months and then every year. Your dentist will check whether your device is working correctly and whether it needs to be adjusted or replaced.

Ask your dentist how to properly care for your oral device. If it does not fit right or your symptoms do not improve, let your dentist know. It is common to feel some discomfort after a device is adjusted until your mouth and facial muscles get used to the new fit.

Sleep apnea can raise your risks of complications if you are having surgery, and it can affect how well you drive. If you need medicine to make you sleep during surgery or pain medicine after surgery, tell your healthcare provider that you have sleep apnea. Your provider may have to take extra steps to make sure that your airway stays open during the surgery and that your pain medicine doesn’t make it harder for your airway to stay open.

Untreated sleep apnea can make you sleepy during the day and can make it difficult for you to pay attention and make decisions while you drive. This can cause road accidents. Pay attention to your symptoms and do not drive if you feel very tired or sleepy.

Consider participating in a clinical trial so clinicians and scientists can learn more about sleep apnea and related disorders. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat or prevent disease.

All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.

For information about participating in clinical research, visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with sleep apnea at Clinicaltrials.gov.