The below example report describes a patient's situation, the results of some tests and mentions CPAP as a treatment for obstructive sleep apnea. CPAP is continuous positive airway pressure and is delivered via a mask to the patient's nose or the patient's nose and mouth. (Some masks cover one, some both). CPAP is typically prescribed after the diagnosis of OSA is made from a sleep study (i.e., after a PSG test). To determine the correct amount of pressure and the right mask type and size, and also to make sure the patient can tolerate this therapy, a "CPAP titration study" is recommended. This is the same as a "PSG" but with the addition of the mask applied so the technician can increase the airway pressure inside the mask as needed, until all, or most, of the patient's airway obstructions are eliminated.