A method and CPAP apparatus for automatically adjusting a continuous positive airway treatment pressure delivered to a patient responds in different manners according to the type of breathing problem. If a respiratory event is an apnea at a treatment pressure below a first value, then the treatment pressure is increased in one manner. If the respiratory event is a partial upper airway obstruction at a treatment pressure below a second value, then the treatment pressure is increased in a different manner; where the first pressure value is less than the second pressure value. In particular, obstructive and central apneas are treated differently by the apparatus.