A method of treating lung disease, such as asthma or COPD, is provided that includes determining a parameter indicative of a patients pulmonary mechanics (such as, without limitation, airway resistance or lung compliance), and delivering positive pressure support to the airway of the patient, wherein the pressure level (which may be constant or variable) of the positive pressure support during at least a portion of the inspiratory phase of the patient is determined based on the determined parameter.
