Obstructive sleep apnea (OSA) is a condition where the soft tissues in your throat repeatedly collapse during sleep, blocking your airway and interrupting your breathing. An estimated 83.7 million adults in the United States have it, roughly 32% of the adult population, and many don’t know it. It ranges from a mild nuisance to a serious health risk depending on how often those breathing pauses happen each night.
What Happens in Your Airway
When you’re awake, the muscles in your throat keep your airway open without any effort. During sleep, those muscles relax. For most people, that relaxation is harmless. But in people with OSA, the surrounding tissues, particularly the tongue and soft palate, shift backward and collapse into the airway. This blocks airflow for seconds at a time, sometimes dozens or even hundreds of times per night.
MRI studies of people during natural sleep have revealed that OSA patients tend to have an oversized tongue and soft palate, a narrower airway cross-section, and a lower-positioned hyoid bone (the small bone at the base of the tongue). The position of that bone and the space behind the soft palate are key factors in determining how severely the airway collapses. During each collapse, the tongue displaces further backward than it does in healthy sleepers, and the airway space shrinks dramatically. Your brain senses the drop in oxygen, briefly rouses you enough to reopen the airway, and the cycle starts again, often without you ever fully waking up or remembering it.
Common Symptoms
The most recognizable sign is loud, disruptive snoring, often punctuated by gasping, choking, or silent pauses that a bed partner notices. But snoring alone doesn’t confirm OSA, and not everyone with OSA snores loudly.
Daytime symptoms are what typically drive people to seek help. Excessive daytime sleepiness is the most common complaint, the kind of tiredness that persists no matter how many hours you spent in bed. Morning headaches are frequent, likely caused by fluctuating oxygen and carbon dioxide levels overnight. Other symptoms include waking up with a dry mouth, needing to urinate multiple times during the night (nocturia), nighttime acid reflux, and difficulty concentrating during the day. Some people develop insomnia because the repeated micro-arousals fragment sleep so badly that staying asleep becomes difficult.
Who Is Most at Risk
OSA affects men more than women. In U.S. adults, the prevalence is about 39% in men and 26% in women, and rates climb with age. Obesity is a major driver because excess tissue around the neck and throat narrows the airway, but OSA also occurs in people at a healthy weight, especially those with certain facial and jaw structures.
Neck circumference is one of the strongest physical predictors of OSA, outperforming even BMI, snoring history, gender, and age in some research. A thicker neck generally means more soft tissue surrounding the airway. Other structural risk factors include a recessed jaw (retrognathia), a small lower jaw (micrognathia), a high arched palate, and enlarged tonsils. In children, enlarged tonsils and adenoids are the most common cause, affecting about 2% of kids.
How It’s Diagnosed
Diagnosis centers on measuring how many times per hour your breathing stops or becomes significantly shallow during sleep. This measurement, called the Apnea-Hypopnea Index (AHI), defines severity:
- Mild: 5 to 14 events per hour
- Moderate: 15 to 30 events per hour
- Severe: more than 30 events per hour
The gold standard is an in-lab sleep study (polysomnography), where you spend a night in a sleep center wired to sensors that track your breathing, oxygen levels, brain waves, and body movements. Home sleep tests are increasingly common and more convenient. They use portable equipment that monitors many of the same signals in your own bed. Compared to in-lab testing, home tests detect about 80% of OSA cases and correctly rule it out about 83% of the time. That means they miss roughly 1 in 5 people who actually have the condition, so a negative home test doesn’t always mean you’re in the clear, especially if your symptoms are strong. Treatment outcomes, including sleepiness improvement and long-term therapy use, are similar regardless of which test leads to your diagnosis.
Health Risks of Untreated OSA
Left untreated, OSA does far more than cause fatigue. The repeated drops in blood oxygen and the stress of constant micro-arousals put significant strain on the cardiovascular system. Severe sleep apnea increases the risk of heart failure by 140%, stroke by 60%, and coronary heart disease by 30%. One large study found that people with an AHI of 20 or higher had more than four times the odds of stroke compared to those without sleep apnea, independent of other risk factors like high blood pressure, smoking, or diabetes.
OSA also disrupts metabolism. People with the condition tend to have higher blood glucose levels and greater insulin resistance, which raises the risk of developing type 2 diabetes. This metabolic effect appears to exist even after accounting for obesity, meaning the oxygen deprivation itself plays a role. In one large study, abnormal glucose tolerance nearly doubled (from about 9% to 15%) as sleep apnea severity increased. The repeated oxygen drops overnight seem to directly interfere with how the body processes sugar.
CPAP Therapy
Continuous positive airway pressure (CPAP) is the most widely used and effective treatment for moderate to severe OSA. The machine delivers a steady stream of pressurized air through a mask you wear during sleep. That pressure acts as a pneumatic splint, keeping your airway open so the surrounding tissues can’t collapse inward. Unlike a ventilator, CPAP doesn’t breathe for you. You breathe normally; the air pressure simply prevents the obstruction.
During a titration study, the pressure is typically started at a low level and gradually increased until breathing events are eliminated. The benefits include improved sleep quality, reduced or eliminated snoring, and noticeably less daytime sleepiness. The biggest challenge with CPAP is consistent use. Mask discomfort, nasal dryness, and feeling claustrophobic are common complaints, but most modern machines offer features like heated humidifiers and auto-adjusting pressure that help. Research shows that about 89% of patients who stick with CPAP use it for more than four hours on at least 70% of nights, which is the threshold generally considered effective.
Alternatives to CPAP
Oral Appliances
For mild to moderate OSA, or for people who can’t tolerate CPAP, a custom-fitted oral appliance is often the next option. The most common type, a mandibular advancement device, looks like a sports mouthguard and works by repositioning the lower jaw and tongue forward to keep the airway open. These devices are most effective for people with mild to moderate OSA and those with an overbite. Side effects can include jaw discomfort, excess salivation, or dry mouth, and insurance coverage varies, so out-of-pocket costs can be significant.
Surgical Options
Surgery aims to permanently widen the airway by modifying the structures that cause obstruction. The most common procedure removes excess tissue from the throat, including the uvula and parts of the soft palate. Other approaches reposition the tongue’s muscle attachment point to prevent it from falling backward, or advance the upper and lower jaw bones forward to enlarge the entire airway. In children, removing enlarged tonsils and adenoids often resolves the problem entirely. For adults, surgery is generally considered when CPAP and oral appliances haven’t worked or aren’t tolerated. A less invasive option uses radiofrequency energy to shrink airway tissues without major surgery.
Nerve Stimulation
A newer treatment for moderate to severe OSA involves a small device implanted in the chest that stimulates the nerve controlling the tongue. A sensor near the diaphragm detects your breathing pattern, and the device sends a mild electrical signal to push the tongue forward in sync with each breath, keeping the airway clear. You turn it on at bedtime with a remote control. This option is typically reserved for people who haven’t had success with CPAP and don’t have major structural abnormalities blocking the airway.
Lifestyle Changes That Help
Weight loss is one of the most effective non-device interventions. Because excess tissue around the neck directly contributes to airway narrowing, even a 10% reduction in body weight can meaningfully reduce the number of breathing events per hour. Sleeping on your side rather than your back helps prevent the tongue and soft palate from falling into the airway by gravity. Avoiding alcohol and sedatives before bed matters because these substances relax the throat muscles further, worsening collapse. None of these changes replace treatment for moderate or severe OSA, but they can reduce severity and improve how well other treatments work.