Sleep apnea is a breathing disorder that occurs while you sleep and involves pauses in breathing with associated drops in the oxygen levels of the blood, increases in heart rate, and brief periods of waking up. In order to treat these episodes, continuous positive airway pressure (CPAP) is used to keep the airway open. This is delivered through a CPAP mask, of which there are many different styles. Learn about the CPAP mask preferences of others or share your experiences with choosing a CPAP mask.