Sleep Apnea

Sleep apnea is a condition marked by abnormal breathing during sleep. People with sleep apnea have multiple extended pauses in breath when they sleep. These temporary breathing lapses cause lower-quality sleep and affect the body’s supply of oxygen, leading to potentially serious health consequences.

Sleep apnea is one of the most common sleep disorders in the United States. It can affect children and adults and people of both sexes, although it is more common in men.

Because of sleep apnea’s prevalence and potential health impact, it is important for people to be aware of what sleep apnea is and to know its types, symptoms, causes, and treatments.

What Are the Types of Sleep Apnea?

There are three types of sleep apnea:

• Obstructive Sleep Apnea (OSA): OSA occurs when the airway at the back of the throat becomes physically blocked. That obstruction causes temporary lapses in breath.
• Central Sleep Apnea (CSA): CSA happens because there is a problem with the brain’s system for controlling muscles involved in respiration, leading to slower and shallower breathing.
• Mixed Sleep Apnea: When a person has both OSA and CSA at the same time, it is referred to as mixed sleep apnea or complex sleep apnea.

Because the underlying causes are distinct, there are important differences in the symptoms, causes, and treatments of OSA and CSA.

How Common Is Sleep Apnea?

Obstructive sleep apnea is estimated to affect between 2-9% of adults in the United States, but many cases are believed to go undiagnosed, which fits with studies that have found considerably higher rates of OSA. Precise prevalence is hard to determine because studies have used different criteria for diagnosing the condition. A consistent finding, though, is that OSA affects men more than women. It can occur in people of any age but is more common in older adults.

Central sleep apnea has been found to affect around .9% of adults over the age of 40. It is found much more frequently in men than in women.

As this data demonstrates, OSA is much more common than CSA. For this reason, when people talk about “sleep apnea,” they are generally referring to OSA.

Symptoms

All three types of sleep apnea share certain common symptoms:

• Disrupted breathing in which a person’s respiration can become labored or even stop for up to a minute at a time
• Excessive daytime sleepiness
• Morning headaches
• Irritability
• Limited attention span or difficulty thinking clearly

Many of these symptoms arise because of poor sleep and decreased oxygen levels that occur as a result of interrupted breathing.

Some additional symptoms are connected to obstructive sleep apnea:

• Snoring, including snoring that is especially loud and involves gasping, choking, or snorting that may cause a person to briefly wake up
• Morning sore throat or dry mouth
• Frequent need to wake up to urinate (nocturia)

Chronic snoring is the most common symptom of OSA, but that doesn’t mean that everyone who snores has sleep apnea. Snoring is not a frequent symptom in people with CSA.

In general, a person with sleep apnea is not aware of their breathing problems at night. For that reason, they often only find out about the issue from a bed partner, family member, or roommate. Excessive daytime sleepiness is the most likely symptom to be noticed by people with sleep apnea that live alone.

Causes

Obstructive sleep apnea occurs when a person’s airway becomes blocked during sleep. Multiple factors have been found to increase the risk of blockage and OSA:

• Anatomical characteristics. The size and positioning of a person’s neck, jaw, tongue, tonsils, and other tissue near the back of the throat can directly affect airflow.
• Obesity. Being overweight is a leading cause of OSA and may be an underlying risk factor in up to 60% of cases. Obesity contributes to anatomical narrowing of the airway, and research has found that a 10% increase in weight can equate to a six-fold increase in OSA risk.

• Use of sedatives, including alcohol. Sedative medications and drugs can cause tissue in the throat to relax, making it easier for the airway to become obstructed.
• Family history. People who have one or more close relatives with OSA are more likely to develop OSA themselves.
• Cigarette smoking. People who smoke, especially heavy smokers, have been found to have OSA at a higher rate than people who don’t smoke.
• Sleeping on your back. This sleeping position makes it easier for tissue to collapse around the airway and cause blockages.
• Nasal congestion. People whose ability to breathe through the nose is reduced because of congestion are more likely to experience OSA.
• Hormone abnormalities. Hormone conditions like hypothyroidism(underactive thyroid) and acromegaly (excess growth hormone) may increase the risk of OSA by causing swelling of tissue near the airway and/or contributing to a person’s risk of obesity.

In CSA, breathing is affected in a different way than in OSA. Instead of an obstruction causing breathing lapses, the problem arises in how the brain communicates with the muscles responsible for respiration. In particular, the brain stem fails to adequately perceive the levels of carbon dioxide in the body, leading to breathing that is slower and shallower than it should be.

CSA is typically connected to an underlying medical condition. For example, a stroke, infection of the brain, or in rare cases a brain tumor may damage the brain stem. Pain medicines like opioids can also interfere with this normal process of breathing.

Heart failure is considered to be a risk factor for CSA, and CSA can also arise when a person’s oxygen levels are thrown off because they are at high altitude.

What Are the Health Risks of Sleep Apnea?

Sleep apnea can lead to sleep deprivation from constant nightly interruptions and shallower overall sleep. Lack of sleep is associated with far-reaching health consequences that affect a person physically, mentally, and emotionally, and as a result, it comes as no surprise that sleep apnea has been tied to diverse health problems.

Because of how it affects oxygen balance in the body, untreated sleep apnea raises dangers for various types of cardiovascular issues including high blood pressure, heart attack, heart disease, and stroke.

Treatments

If you have symptoms of sleep apnea, you should make sure to talk with a doctor. Without understanding the root causes of your sleep apnea, it is difficult to treat. When necessary, the doctor can recommend an overnight sleep study to analyze your sleep, including your breathing.

If a person is diagnosed with OSA or CSA, treatment is often effective at improving sleep and reducing the risks of long-term health complications. A doctor familiar with a patient’s situation is in the best position to address potential benefits and risks of treatments and make specific recommendations.

Lifestyle changes, such as losing weight, reducing use of sedatives, and sleeping on your side, can resolve some cases of OSA. Another common treatment is nightly use of a continuous positive airway pressure (CPAP) or bi-level positive airway pressure (BiPAP) machine. These devices push air through a mask and into the airway to keep it open during sleep.

Some types of mouthpieces that hold the jaw or tongue in a specific position are an option for people with certain anatomical features that trigger mild OSA. In addition, though usually not the first treatment option, surgery to remove tissue and expand the airway can be considered. Medications may be prescribed to help with daytime sleepiness in people with this symptom.

Treatment for CSA typically centers on managing the underlying condition, such as a brain infection, heart failure, or altitude adjustment, that causes disordered breathing. CPAP or BiPAP machines or supplemental oxygen may help some patients as well.

About Our Editorial Team

Eric Suni

Staff Writer

Eric Suni has over a decade of experience as a science writer and was previously an information specialist for the National Cancer Institute.

Joel Gould

Dentist, Sleep Apnea Expert

DDS

Dr. Gould has practiced dentistry since 2001 and specializes in treating obstructive sleep apnea. He is the founder of the Sleep Restoration Program.