When the chief complaint is (or should be) dyspnea in adults

Dyspnea, "a subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity," is an important and challenging complaint associated with a wide variety of adverse clinical outcomes, including hospitalizations for chronic obstructive pulmonary disease and cardiac mortality. Although up to 85% of cases are caused by asthma, chronic obstructive pulmonary disease, interstitial lung disease, pneumonia, cardiac ischemia, congestive heart failure, or psychogenic disorders, a systematic approach can help to identity uncommon, but important, causes of dyspnea. In this review that includes clinical examples as well as a didactic review of currently available information, we suggest a step-wise approach to the evaluation of the adult patient with dyspnea. It is also important to avoid 3 possible pitfalls: accepting a cause for dyspnea in which the element identified is only part of a syndrome which includes that element; accepting a single cause for dyspnea when the cause is multifactorial; and failing to recognize a diagnosis and cause of dyspnea is incorrect and has been assumed without rigorous confirmation, when a patient with a specific diagnosis is referred for "failing to respond to treatment."