Breathlessness is a term used to describe a subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity. It is a common, often debilitating symptom that is distressing for both the person and their carers (Parshall et al. [218]). It is a problem where there is a complex interplay between physical, psychological, emotional and functional factors because the impairment of breathing has life‐threatening connotations. Because of this interplay the underlying pathology may not correlate with the patient's perception of their symptoms (Jolley and Moxham [133]). Box 27.9 lists some of the impacts that may be expressed by people who experience breathlessness.