What Is Sleep Apnea?

What are the Symptoms?

At night, sleepers might snort or choke or experience silent pauses mixed with chronic snoring. During the day, people with sleep apnea may experience persistent fatigue and drowsiness, morning headaches, difficulty concentrating, irritability, forgetfulness, anxiety, or mood swings. The combination of disturbed sleep and oxygen deprivation can lead to high blood pressure, heart problems, and alterations in gray and white matter in the brain. It also can increase the risk of stroke and death.

What are the Causes?

There are three types of sleep apnea: obstructive sleep apnea, central sleep apnea, and complex sleep apnea syndrome. In obstructive sleep apnea, the obstruction is caused by relaxed throat muscles, such as those supporting the uvula, tonsils, and tongue, or by a narrow airway. The condition is exacerbated by smoking, drinking alcohol, or using sedatives and tranquilizers. About 70 percent of people with obstructive sleep apnea are overweight. In central sleep apnea, which is less common, the obstruction results from failure of the brain’s neural networks to send signals to muscles that control breathing. Central sleep apnea tends to be associated with other neurologic disorders, such as Parkinson’s disease and myotonic dystrophy, and damage to the brainstem from stroke. It can also result from long-term opioid use, which may alter breathing patterns during sleep. Complex sleep apnea syndrome occurs when the two disorders overlap.

How is Sleep Apnea Diagnosed?

Depending on the condition’s severity, a doctor may prescribe a take-home test or an overnight examination at a sleep center. The at-home test uses sensors to document pauses in breathing and absence of breathing; a pulse oximeter to measure oxygen levels; a mask with tubes that connect to the nostrils; and sensors on the abdomen and chest to measure the rise and fall of breathing. At a sleep center, the patient would undergo a polysomnogram, with electrodes placed on the head, chest, and legs to record brain activity, eye and leg movement, muscle tone, heart rhythm, and breathing. After one night of sleep, the data are presented to a physician for analysis. 

How is it Treated?

The most common treatment for obstructive sleep apnea is a continuous positive airway pressure (CPAP) machine, which has a mask that fits over the nose and mouth and gently delivers air through a tube to open the airway. Those who require more respiratory support may need a bilevel positive airway pressure (BiPAP) machine, which delivers two pressures of air, one for inhaling and the other for exhaling. Obstructive sleep apnea also can be treated with a device that stimulates the hypoglossal nerve, which controls tongue movement. Approved by the U.S. Food and Drug Administration in 2014, the minimally invasive procedure called upper airway stimulation involves implanting a pacemaker-like impulse generator under the clavicle with sensors and stimulators that signal and stimulate the nerve to move the tongue forward to allow the patient to breathe. The device comes with a remote control that allows patients to adjust and turn the device on and off. To treat CSA, sleep specialists may prescribe adaptive servo-ventilation, a positive airway pressure machine that delivers air pressure based on pauses in breathing it detects. In addition to devices, sleep apnea can be managed through lifestyle changes such as losing weight, avoiding alcohol, quitting smoking, and moderating sleep positions.

What Research is Being Done?

The National Institutes of Health (NIH) supports studies at the NIH lab and other institutions that look at ways to prevent and treat sleep disorders, including sleep apnea.

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