Obstructive Sleep Apnea (OSA)

What happens in OSA

During sleep, the muscles that hold the throat open relax. In people with OSA, the airway behind the tongue and soft palate narrows or collapses:

• an apnea is a complete stop in airflow for 10 seconds or more
• a hypopnea is a partial reduction in airflow with a drop in oxygen or a brief arousal

Each event drops blood oxygen and triggers a surge of stress hormones and a micro-awakening to reopen the airway. These awakenings fragment sleep, usually without the person remembering them. This can happen dozens of times an hour.

Symptoms

At night

• loud, habitual snoring
• pauses in breathing, choking or gasping, often noticed by a bed partner
• restless sleep
• waking often, including to urinate (nocturia)
• night sweats
• dry mouth or sore throat on waking

During the day

• excessive daytime sleepiness: dozing while reading, watching TV or driving
• unrefreshing sleep despite enough hours in bed
• morning headaches
• poor concentration, memory problems, irritability, low mood
• reduced libido and erectile dysfunction

Women more often report insomnia, fatigue, mood changes and headaches rather than classic snoring and sleepiness, which contributes to under-diagnosis.

In children

Snoring, mouth breathing, restless sleep, bedwetting, daytime hyperactivity, attention problems and poor growth. The most common cause is enlarged tonsils and adenoids.

Risk factors

• obesity, especially a large neck (over 17 inches or 43 cm in men, 16 inches or 41 cm in women)
• male sex, and women after menopause
• older age
• narrow airway, large tonsils, a recessed jaw, large tongue
• nasal congestion
• family history
• alcohol and sedatives before bed
• smoking
• conditions such as hypothyroidism, acromegaly and Down syndrome

Health effects of untreated OSA

• high blood pressure, particularly resistant hypertension
• atrial fibrillation and other arrhythmias
• coronary heart disease and heart failure
• stroke
• type 2 diabetes and insulin resistance
• motor vehicle and workplace accidents from drowsiness
• depression and cognitive decline
• complications during surgery and anesthesia

Diagnosis

1. Screening questionnaires such as STOP-BANG and the Epworth Sleepiness Scale.
2. Sleep testing: - home sleep apnea test (HSAT): measures breathing, oxygen and heart rate at home; suitable for many adults with a high likelihood of moderate to severe OSA and no major other conditions - in-lab polysomnography: a full overnight study including brain waves; used for complex cases, children, or when a home test is negative but suspicion remains
3. Severity is measured by the apnea-hypopnea index (AHI), the number of events per hour:

Treatment

CPAP (continuous positive airway pressure)

A machine delivers gentle air pressure through a mask, keeping the airway open. It is the most effective treatment for moderate to severe OSA. Benefits include less snoring, better sleep, less sleepiness and lower blood pressure. Getting used to CPAP takes time; mask fitting, heated humidification and auto-adjusting machines help. Using it for most of the night, every night, gives the best results.

Weight loss

Losing weight can substantially reduce the AHI and sometimes resolve OSA. Tirzepatide is FDA-approved for moderate to severe OSA in adults with obesity. Bariatric surgery is an option for some people with severe obesity.

Oral appliances

A custom mandibular advancement device, fitted by a dentist, holds the lower jaw forward during sleep. It is effective for mild to moderate OSA and for people who cannot tolerate CPAP.

Positional therapy

Some people have apneas mainly when lying on their back. Devices that encourage side-sleeping can help.

Surgery and implants

• tonsil and adenoid removal, the main treatment for children
• palate, tongue and jaw surgery for selected adults
• hypoglossal nerve stimulation: an implanted device that moves the tongue forward during sleep, for some people who cannot use CPAP

Lifestyle

• avoid alcohol and sedatives in the evening
• stop smoking
• treat nasal congestion
• keep regular sleep hours

Frequently asked questions

What are the signs of sleep apnea?

Common signs are loud snoring, pauses in breathing or gasping during sleep noticed by a partner, waking unrefreshed, daytime sleepiness, morning headaches, poor concentration and frequent night-time urination.

How is sleep apnea diagnosed?

It is diagnosed with a sleep study, either a home sleep apnea test or an overnight study in a sleep lab. The number of breathing interruptions per hour (AHI) determines the severity.

Is sleep apnea dangerous?

Untreated moderate to severe OSA increases the risk of high blood pressure, atrial fibrillation, heart disease, stroke, diabetes and drowsy-driving accidents. Treatment reduces symptoms and some of these risks.

Can sleep apnea be cured?

Some people can resolve OSA with significant weight loss, and children often improve after tonsil and adenoid removal. For most adults, OSA is controlled rather than cured, with CPAP, oral appliances or other treatments.

What if I cannot tolerate CPAP?

Work with your sleep team on mask fit, humidity and pressure settings, as many problems can be solved. Alternatives include oral appliances, positional therapy, weight loss, surgery and hypoglossal nerve stimulation.