The Approach to the Patient With Chronic Dyspnea of Unclear Etiology

Dyspnea is defined by the American Thoracic Society as a “subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity.”1 It is a common nonspecific symptom in patients presenting to both primary care and subspecialty medical providers. Dyspnea can be the presenting complaint for a large variety of disease processes and as a result, patients see several specialists for upwards of 2 years prior to formal diagnoses (Table 1).2–4 For example, nearly 90% of people with pulmonary arterial hypertension (PAH) present with dyspnea on exertion,5 but distinguishing between dyspnea caused by PAH from dyspnea caused by other cardiac or pulmonary disease—or a whole host of other conditions—is challenging. In this review, we will discuss the diagnostic approach to patients presenting with chronic dyspnea of inexact etiology.