Acclimization therapy for first time CPAP and NIV users

A method of acclimatizing a patient to provide continuous positive airway pressure (CPAP) therapy, including operating a device for treating sleep disordered breathing (SDB). The device provides continuous positive airway pressure to the patient during sleep via a mask configured to provide a seal with respect to airways of the patient. The method comprises applying full therapeutic pressure during a first session, monitoring a mask pressure during application of the full therapeutic pressure, calculating a difference between the full therapeutic pressure and the mask pressure, comparing the difference to a threshold representing an acceptable level of leak, generating a first signal in response to said comparing, and in response to said first signal indicating a fault in the seal, decreasing an applied pressure to below the full therapeutic pressure during the first session in order to improve the seal of the mask against the patient's face.