CPAP: Continuous positive airway pressure. ... Patients with obstructive sleep apnea treated with CPAP wear a face mask during sleep which is connected to a pump (CPAP machine) that forces air into the nasal passages at pressures high enough to overcome obstructions in the airway and stimulate normal breathing. Apneais the cessation of breathing. Duringapnea, there is no movement of the muscles of inhalation, and the volume of the lungs initially remains unchanged.
