A system for guiding transitions between therapy modes provided to a patient suffering from sleep disordered breathing, comprising: a flow generator configured to supply a plurality of therapy modes to the patient, the flow generator being further configured to: receive input indicating a second therapy mode to be transitioned to following provision of a first therapy mode, said second therapy mode being different from said first therapy mode; wherein the first and second therapy modes are selected from the group comprising: CPAP therapy mode, AutoSet therapy mode, VAUTO therapy mode, and S/ST/T therapy mode; effect a transition from the first therapy mode to the second therapy mode in accordance with instructions as to how to perform the transition, the instructions being indicative of at least one default treatment parameter suitable for the second therapy mode and any changes made by an operator to each said default treatment parameter prior to the transition, characterized in that said transition between said first and second modes involves moving at least one treatment parameter of the first therapy mode substantially continuously to a second level of a corresponding treatment parameter appropriate for the second therapy mode. a flow generator configured to supply a plurality of therapy modes to the patient, the flow generator being further configured to: receive input indicating a second therapy mode to be transitioned to following provision of a first therapy mode, said second therapy mode being different from said first therapy mode; wherein the first and second therapy modes are selected from the group comprising: CPAP therapy mode, AutoSet therapy mode, VAUTO therapy mode, and S/ST/T therapy mode; effect a transition from the first therapy mode to the second therapy mode in accordance with instructions as to how to perform the transition, the instructions being indicative of at least one default treatment parameter suitable for the second therapy mode and any changes made by an operator to each said default treatment parameter prior to the transition, characterized in that said transition between said first and second modes involves moving at least one treatment parameter of the first therapy mode substantially continuously to a second level of a corresponding treatment parameter appropriate for the second therapy mode. receive input indicating a second therapy mode to be transitioned to following provision of a first therapy mode, said second therapy mode being different from said first therapy mode; wherein the first and second therapy modes are selected from the group comprising: CPAP therapy mode, AutoSet therapy mode, VAUTO therapy mode, and S/ST/T therapy mode; effect a transition from the first therapy mode to the second therapy mode in accordance with instructions as to how to perform the transition, the instructions being indicative of at least one default treatment parameter suitable for the second therapy mode and any changes made by an operator to each said default treatment parameter prior to the transition, characterized in that said transition between said first and second modes involves moving at least one treatment parameter of the first therapy mode substantially continuously to a second level of a corresponding treatment parameter appropriate for the second therapy mode.