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. Stopping breathing 5 to 14 times an hour is mild sleep apnea, 15 to 29 times an hour is moderate, and 30 or more times an hour is severe.

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.