A breathing assistance apparatus and method of controlling a breathing assistance apparatus is disclosed. Particularly, the breathing assistance apparatus is controlled such that it has a drying cycle to enable drying of the tubing that supplies gases to a user and prevent the harboring of pathogens within the tube. The drying cycle is preferably operated automatically by internal controllers in the apparatus. However, it may be manually activated by pressing a button on the apparatus. The drying cycle is preferably activated at the end of a user's treatment session.
