Continuous positive airway pressure (CPAP) is a medical device used primarily to treat obstructive sleep apnea. It works by delivering a steady stream of air through a mask that keeps the airways open during sleep, preventing interruptions in breathing. The CPAP machine consists of a motor, a hose, and a mask. The motor generates air pressure, which travels through the hose and into the mask worn over the nose or mouth. This treatment helps improve sleep quality and reduces the risk of complications associated with sleep apnea, such as heart disease and high blood pressure.