Nasal CPAP is given through a mask that is placed and secured over the person's nose or nose and mouth. Slight positive pressure is used to increase the amount of air breathed in without increasing the work of breathing.

CPAP is useful for children with collapsible airways, small lung volumes, or muscle weakness that interferes with adequate ventilation.

CPAP is also used for adults with COPD, acute respiratory failure, and sleep apnea.