Diagnostic evaluation of dyspnea.

Dyspnea is a common symptom and, in most cases, can be effectively managed in the office by the family physician. The differential diagnosis is composed of four general categories: cardiac, pulmonary, mixed cardiac or pulmonary, and noncardiac or nonpulmonary. Most cases of dyspnea are due to cardiac or pulmonary disease, which is readily identified with a careful history and physical examination. Chest radiographs, electrocardiograph and screening spirometry are easily performed diagnostic tests that can provide valuable information. In selected cases where the test results are inconclusive or require clarification, complete pulmonary function testing, arterial blood gas measurement, echocardiography and standard exercise treadmill testing or complete cardiopulmonary exercise testing may be useful. A consultation with a pulmonologist or cardiologist may be helpful to guide the selection and interpretation of second-line testing.