Sleep apnea is breathing that stops during sleep. When people have sleep apnea, they stop breathing and may have breathing that is shallow. The problem can be mild to severe, based on how often your lungs don't get enough air. For adults, mild sleep apnea means that breathing stops 5 to 14 times an hour. Moderate sleep apnea means breathing stops 15 to 29 times an hour. And with severe sleep apnea, breathing stops 30 or more times an hour.

There are two main types of sleep apnea. Obstructive sleep apnea is caused by blocked airways. And central sleep apnea is 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.