Continuous positive airway pressure (CPAP) is the primary treatment for obstructive sleep apnea (OSA). A small mask or nasal cannula is applied to the nose which is connected by tubing. Air pressure is controlled by a generator, similar to an air purifier. The pressurized air prevents the airway from collapsing and allows the lungs and heart to work under less stress. The treatment is effective immediately, and symptoms begin disappearing the next morning.