Sleep apnea occurs when an adult regularly stops breathing or has slowed breathing during sleep for 10 seconds or longer. It can be mild, moderate, or severe, based on the number of times per hour breathing stops (apnea) or slows (hypopnea).

The three main types of sleep apnea are:

Obstructive sleep apnea (OSA), which is the result of blocked airflow during sleep, such as from narrowed airways. Other factors, such as obesity, often contribute to obstructive sleep apnea.

Central sleep apnea, which results from a problem with how the brain signals the breathing muscles. This type of apnea can occur with conditions such as heart failure, brain tumors, brain infections, and stroke.

Mixed sleep apnea, which is a combination of obstructive and central sleep apnea.

A person who has sleep apnea may snore loudly and have restless sleep with difficulty breathing. The person may wake up with a headache and be very tired throughout the day.

Sleep apnea may improve with changes in sleep habits, such as not sleeping on your back. Sometimes devices to help breathing during sleep are useful, and occasionally surgery may help.