Sleep apnea is breathing that stops during sleep. The problem can be mild or severe, based on how often your lungs don't get enough air. This may happen from 5 to more than 50 times an hour.

The two main types of sleep apnea are obstructive sleep apnea, caused by blocked airways, and central sleep apnea, caused by a problem with how the brain signals the breathing muscles.

Sleep apnea can cause you to snore loudly. People with sleep apnea often have sleep problems and are tired during the day. And they are more likely to have high blood pressure and some heart problems.