What Is Sleep Apnea?

Sleep apnea is a condition where breathing repeatedly stops and starts during sleep. The most common form, obstructive sleep apnea (OSA), happens when the muscles in your throat relax enough to block your airway — sometimes dozens of times per hour.

Each pause forces a brief, partial awakening as your brain wakes the body just enough to breathe. You don't remember it. But your sleep is being shredded into fragments, which is why people with untreated apnea feel exhausted no matter how long they spend in bed.

How common is it?

Estimates suggest nearly 1 billion adults worldwide have some degree of obstructive sleep apnea, and the majority are undiagnosed. It's especially under-recognized in women, who often present with fatigue and insomnia rather than the classic loud-snoring picture.

What causes it?

OSA is mechanical: something is narrowing the airway during sleep. Risk factors include:

• Excess weight, particularly around the neck
• A naturally narrow airway, large tonsils, or a recessed jaw
• Being male, or post-menopausal female
• Family history of sleep apnea
• Nasal congestion, smoking, or alcohol use
• Certain medical conditions: hypertension, type 2 diabetes, hypothyroidism

Symptoms to watch for

The full list lives in 10 signs of sleep apnea, but the headline ones are:

1. Loud snoring most nights
2. Gasping or choking during sleep (often noticed by a partner)
3. Excessive daytime sleepiness
4. Morning headaches or dry mouth
5. Difficulty concentrating
6. Mood changes — irritability, low mood

Why it matters

Untreated OSA isn't just about feeling tired. Long-term, it's linked to higher risk of high blood pressure, heart disease, stroke, and type 2 diabetes. Treating it improves not just energy but cardiovascular outcomes — which is why screening matters.

How it's diagnosed

Diagnosis happens through a sleep study (polysomnography), either in a sleep lab or with a home sleep apnea test. Results report an AHI (apnea–hypopnea index) — the number of breathing disruptions per hour — and severity is graded mild, moderate, or severe.

Treatment options

Modern treatment is more flexible than it used to be:

• CPAP therapy — the gold standard for moderate-to-severe OSA. See CPAP and alternatives.
• Oral appliances — fitted by a sleep dentist, ideal for mild-to-moderate OSA.
• Positional therapy — for people whose apnea is mostly back-sleeping.
• Weight management — modest weight loss can substantially improve mild OSA.
• Surgery or implants — for select cases (e.g., hypoglossal nerve stimulation).

The bottom line

Sleep apnea is common, treatable, and worth taking seriously. If any of the warning signs above feel familiar, the right next step is screening, not silence. Our quiz can help you understand whether your symptoms warrant a professional evaluation.