Chronic dyspnoea is a commonly encountered clinical manifestation. This is normally worsened by exertion and relieved by taking rest. The heart and lungs are the organs that provide the vital driving force during exertion. Any disorder that impairs the function of these vital organs will lead to a reduction in effort tolerance. The severity of dyspnoea and the level of effort tolerance are normally commensurate with the degree of organ dysfunction. Besides, any weight gain also affects the level of effort tolerance, as the extra weight will add to the load of the heart and lungs. Apart from this, the haemoglobin level will determine the oxygen-carrying capacity of the blood and how much “fuel” can be consumed in the tissue.
In this lecture, I will discuss approaches for evaluating patients with chronic dyspnoea and how we may optimise the treatment through a good understanding of the underlying pathophysiology.