The symptom of breathlessness may be caused by diseases of the lung, heart, obesity, poor fitness, anaemia or “dysfunctional breathing” (DB).

The term “dysfunctional breathing” is not clearly defined but it refers to disordered respiratory function, which includes subjective awareness of the process of breathing. It may cause or be associated with a variety of complaints. The term “functional breathing complaints” could be used for respiratory complaints with insufficient organic explanation.

There are a number of terms that are used loosely interchangeably to denote this condition. These include “hyperventilation syndromes” , “behavioural breathlessness” , “disproportionate breathlessness” and “psychogenic dyspnoea”. Perhaps the most widely used term is “hyperventilation syndromes” (HVS) which refer to respiratory complaints that are associated with disturbed respiratory function without physical abnormalities of the lungs.

There is a spectrum of conditions described under the umbrella term “hyperventilation syndromes”. At one end there are patients who have acute hyperventilation, who suffer episodic severe breathlessness, with or without features of panic attacks (generally called “hyperventilation syndrome”). At the other end, there are patients who have to take periodic deep breaths (the so called “sighing breathlessness”) or complain of being unable to get a really good breath. Between these two extremes, patients present with a variety of descriptions of breathlessness, which usually occurs at rest and may also occur on exertion. The term “dysfunctional breathing” refers to such breathing difficulty.

A diagnosis of dysfunctional breathing is suspected on the basis of the clinical history. This requires an in depth understanding of the ‘language’ one uses to describe the breathing difficulty. The next step is clinical examination and appropriate diagnostic tests to exclude abnormalities of the heart and lungs. The diagnosis can be confirmed using a Cardio-Pulmonary Exercise Test.