Sleep Apnea: Symptoms, Dangers, and Treatment

He sleeps — and then stops breathing. Five seconds. Ten. Then a sharp gasping breath, the body jerks, and he falls back asleep without waking, without remembering. This can happen hundreds of times in a single night. In the morning: exhaustion, daytime sleepiness, headache. "I just don't sleep well."

Sleep apnea is one of the most common and most undiagnosed sleep disorders. Research estimates roughly a billion people worldwide have some form of it, and the majority are unaware.

What happens during apnea

Obstructive sleep apnea (OSA) is the most common form. During sleep, throat muscles relax and soft tissue collapses over the airway. The brain detects falling oxygen levels and sends an arousal signal — the person micro-wakes, often without awareness, to restore breathing. The cycle repeats through the night.

Severity is measured by the apnea-hypopnea index (AHI): episodes per hour. Mild: 5–15. Moderate: 15–30. Severe: over 30 per hour. With severe apnea, breathing may stop more than five hundred times a night.

Apnea and mental health

The link between apnea and mental health conditions is bidirectional and strong. Depression occurs two to three times more frequently in people with sleep apnea than in the general population. Several mechanisms explain this: chronic sleep fragmentation impairs emotional regulation; hypoxia damages brain regions that regulate mood; the sustained stress of repeated micro-arousals depletes the nervous system.

Anxiety disorders are also more common in people with apnea. Cognitive impairment — reduced memory, concentration, and processing speed — is documented in patients with untreated apnea. Some people spend years treating depression only to find, after successful apnea treatment, that a significant portion of their symptoms were apnea-driven.

Risk factors and diagnosis

Classic risk factors include obesity, male sex, age over 40, large neck circumference, smoking, alcohol use, and anatomical features like a small jaw or enlarged tonsils. But apnea also occurs in slender people, in women (especially after menopause), and in children.

Diagnosis is made by polysomnography in a sleep laboratory or home sleep monitoring. If a partner reports that you snore and seem to stop breathing, if you wake with headaches, if you feel sleepy during the day despite adequate sleep time — these are reasons to get evaluated.

Treatment

CPAP therapy — continuous positive airway pressure delivered through a mask — is the standard treatment for moderate to severe apnea. Most patients who adapt to CPAP report dramatic improvements in energy, sleep quality, and mood. For mild apnea: weight loss, positional therapy (avoiding sleeping on the back), and oral appliances can be effective.

If you have symptoms of apnea, do not wait. Early diagnosis and treatment change quality of life profoundly — and reduce the health risks that accumulate from years of untreated disordered breathing.