This invention relates to a patient interface, such as a nasal cannula, comprising a body to be positioned upon a user (preferably such as a user's face), the body including at least one (and preferably a pair of) nasal prong(s), the or each nasal prong including a lumen capable of being fluidly connected thereto for fluid communication with a supply of breathable gas, the or each nasal prong to be in a configuration either inserted into, or to direct a flow of gas toward, a nare or the nares of the user's nose, wherein the body includes at least one element responsive to force(s) or movement(s), or both, experienced by at least a first region of the patient interface.
