Diagnosing Sleep Apnea

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A growing number of people in the United States are being diagnosed with sleep apnea, a disorder characterized by disrupted and irregular breathing that affects the quality of a person’s sleep. Sleep apnea often causes excessive daytime sleepiness, which can affect how well a person functions throughout the day and even lead to serious accidents.Sleep apnea can be effectively managed in a number of ways. In order to plan treatment, an accurate diagnosis must be made. If daytime sleepiness is affecting your quality of life and you believe you are struggling to get a good night’s sleep, it’s important to talk to a doctor.

Learning about sleep apnea can help you have an informed discussion with your doctor about the diagnostic process and next steps for care.

What Is Sleep Apnea?

Sleep apnea is a breathing disorder in which the airway repeatedly closes or narrows throughout the night, restricting airflow and oxygen. There are two main types of sleep apnea: obstructive sleep apnea (OSA) and central sleep apnea (CSA).

Obstructive sleep apnea results from blockage of the airway in the mouth or throat. The blockage is usually caused by relaxation of the tissues in the back of the mouth. The tongue, uvula, tonsils, or soft palate can all potentially touch the back of the throat while sleeping, restricting airflow. This can cause snoring, snorting, or gasping for air.

Central sleep apnea is less common than OSA and occurs when the brain fails to alert the body’s muscles to continuously breathe. As a result, breathing starts and stops, with each pause in breathing lasting about 10 seconds or longer.

How Is Sleep Apnea Diagnosed?

A diagnosis of sleep apnea can only be made after a sleep study confirms you are experiencing breathing problems in your sleep, and other sleep disorders or health problems have been ruled out. In order to determine whether you should be referred for a sleep study, a doctor will first perform a physical exam, ask about symptoms, and collect your personal and family history.

During an evaluation for sleep apnea, a doctor may ask one or more of the following questions:

Do you feel tired or sleepy during the day?
Do you take naps? If so, how often and how long are your naps?
Is it difficult to stay awake performing tasks like driving, reading, or watching TV?
Do you currently smoke, or have you smoked in the past?
Has anyone in your family been diagnosed with sleep apnea?

During the exam, the doctor may also take into consideration whether your weight, neck circumference, or blood pressure put you at higher risk of sleep apnea. Some doctors may request that you fill out a questionnaire about your sleep habits.

If the doctor suspects sleep apnea based on your exam and symptoms, they will likely recommend that you have a sleep study.

Polysomnogram

A polysomnogram is a sleep study in which medical devices are used to monitor a person’s breathing, heart rate, and the electrical activity of their brain waves while they sleep. A person must have a polysomnogram, either in a sleep lab or at home, in order to be diagnosed with sleep apnea.

If you have a polysomnogram at a sleep lab, your health care provider will give you instructions on when to arrive, what to bring with you, and whether you should make any changes to your diet or medications that day.

After acclimating to your room at a sleep lab, a technician attaches monitoring devices to your legs, fingers, chest, and head. The devices measure body processes while you sleep. The data are then translated into stages of sleep, wakefulness, and events where breathing is interrupted.

If the doctor thinks it’s very likely that you have sleep apnea, the sleep study may also involve a positive air pressure (PAP) device. This is called a split-night sleep study. If the polysomnogram results from the first half of the night confirm that you have sleep apnea, a PAP device is used in the second half of the night to help prepare you for ongoing treatment.

A PAP device helps keep the windpipe open by forcing air through a tube and mask fitted to your face while you sleep. Your physiological activity is monitored at different air pressures provided by the PAP device to see which is the best pressure for you.

A polysomnogram at a sleep center may be preferred over a home sleep apnea test if you have heart or lung disease, risk factors for central sleep apnea or a history of other sleep disorders.

Home Sleep Apnea Tests

A home sleep apnea test (HSAT) may be an option for people who are suspected of having moderate to severe obstructive sleep apnea based on their symptoms or physical exam. An HSAT takes fewer measurements than an in-lab sleep study, so it is not the preferred choice for people who are suspected of having central sleep apnea or other sleep disorders.

Additionally, most home sleep apnea tests cannot differentiate between obstructive sleep apnea and central sleep apnea episodes. This is because the home tests do not measure breathing effort.

That said, home sleep apnea tests do provide some benefits. For example, when a person sleeps in the comfort of their own home, they are more likely to have longer periods of sleep. An HSAT can also be used to help determine whether a PAP device is working well or to reevaluate a person if they are still experiencing symptoms after starting treatment.

To set up a home sleep apnea test device, you strap a device across your abdomen and chest, wear an oxygen probe on your finger, and insert a nasal tube.

After you take a test, your doctor reviews the data and works with you to provide the best course of treatment.

Diagnostic Criteria

A diagnosis of obstructive sleep apnea is based on the results of the polysomnogram and the presence or absence of certain symptoms. A polysomnogram records how many apneas, hypopneas, or respiratory effort-related arousals (RERA) occur per hour while a person is asleep.

Apnea: Apnea is when airflow stops for a period of 10 seconds or longer.
Hypopnea: Hypopnea is a period of shallow breathing that lasts for at least 10 seconds and causes a drop in the oxygen level in your blood.
Respiratory effort-related arousal (RERA): RERAs occur when breathing becomes more forced for a period of at least 10 seconds and disrupts sleep.

Common symptoms of sleep apnea include daytime sleepiness, snoring, and morning headaches. Less commonly, people may experience insomnia or nighttime awakenings with an urge to use the bathroom.

People who have no symptoms of sleep apnea can still be diagnosed with this condition if they have 15 or more of these events per hour during a sleep study. For people with symptoms of sleep apnea, at least five events per hour must be recorded in order to confirm the diagnosis.

A diagnosis of central sleep apnea also requires careful consideration of a person’s symptoms and polysomnography results. However, there are several subtypes of central sleep apnea, and each has specific diagnostic criteria. It is particularly important that other health conditions, including other sleep disorders, are ruled out before CSA is diagnosed.

Next Steps After Getting a Diagnosis

If you are diagnosed with sleep apnea, a member of your health care team will explain what type of sleep apnea you have and whether the condition is mild, moderate, or severe. They may also talk about some of the potential health risks associated with sleep apnea and offer precautions against driving if you are frequently sleepy during the day.

Next, a doctor will discuss what kind of treatment is appropriate for your situation. The treatment plan will depend upon what type of sleep apnea you have and the severity of the disorder, as well as your personal preferences.

For most people, sleep apnea is a chronic condition. This means that ongoing treatment usually alleviates symptoms, but stopping treatment may cause symptoms to come back or get worse.

For most people, sleep apnea can be managed with a combination of lifestyle changes and other medical treatments.

Lifestyle changes: Regular physical activity, losing weight, and maintaining healthy sleep habits may relieve symptoms of sleep apnea. Changing sleep position from lying on your side to lying on your back may also help.
Positive airway pressure therapy: PAP therapy is a primary treatment option for OSA and certain types of CSA. A PAP device has a mask that is worn over your nose and mouth during sleep. The mask is connected by a hose to a small machine beside your bed, and the machine pumps air through the hose and mask to open your airway.
Other breathing devices: Apart from PAP, there are also oral appliances that position your tongue or jaw in a way that doesn’t block airflow. These oral appliances may be considered if you are diagnosed with OSA but can’t have PAP therapy.
Mouth and throat exercises: Exercises for your mouth and throat can help strengthen the muscles that can otherwise become loose and block airways during sleep. Exercises may include pronouncing vowels, repositioning the tongue, and chewing while keeping the mouth closed.
Surgery: If neither PAP nor oral appliances are working effectively, surgical treatment may be an option for some people. The goal of surgery is to stabilize or enlarge the upper airway in order to improve airflow. In some cases, surgery may make PAP therapy more tolerable and effective, but it is not likely to cure OSA.
Nerve stimulation: Another option for people who are not able to tolerate PAP therapy is an implanted device that monitors breathing during sleep. It can detect when the tongue interferes with breathing and then stimulate nerves to reposition the tongue. More studies are needed to confirm the efficacy and safety of this treatment option.

Possible Signs of Sleep Apnea

Sleep apnea may present itself in a number of ways. Consider talking with your doctor if you have one or more symptoms of the condition.

Daytime sleepiness: Daytime sleepiness includes feelings of low energy or poor focus. People with sleep apnea may also unintentionally fall asleep during daytime activities.
Loud snoring or gasping for air during sleep: A partner or a family member may notice that you are snoring or experiencing shallow or irregular breathing.
Morning headaches: Morning headaches that occur daily or multiple times a week are reported by some people with obstructive sleep apnea.
Sleep-maintenance insomnia: Waking up multiple times in the night can be a symptom of sleep apnea. Repeated awakenings may lead to more urges to urinate in the night.
Chest pain: Some people with sleep apnea report chest pain at night or early in the morning due to reduced oxygen in the blood.

Risk Factors for Sleep Apnea

A risk factor is anything that increases the likelihood a person will develop a health problem. Risk factors for sleep apnea include personal characteristics and family history.

Large neck circumference: A neck with a circumference greater than 17 inches may indicate excess fat, including tongue fat, that could narrow or block the airway.
Age: Individuals older than 65 are at higher risk for central sleep apnea.
Misaligned jaw: A small lower jaw or an abnormally shaped upper jaw may impact positioning of the tongue, which in turn can block the airway during sleep.
Family history of snoring and apnea: The risk of developing obstructive sleep apnea is approximately 50% greater if a first-degree relative such as a sibling or parent has the condition.

Sleep apnea is also more likely to occur in people that have certain health conditions. People with cardiac conditions, including high blood pressure and heart failure, commonly have sleep apnea. Obstructive sleep apnea in particular is more common among people with epilepsy, and correlates with increased frequency of seizures and more daytime sleepiness.

Untreated sleep apnea can affect a person’s quality of sleep and daily life. However, timely diagnosis and treatment for sleep apnea can prevent complications and relieve symptoms in most cases.