Pulmonary hypertension (PH), defined as elevated pulmonary artery pressure, is common in the general population and associated with increased mortality. Accordingly, physicians commonly encounter patients with dyspnea, exercise intolerance, and/or right heart failure who have elevated pulmonary artery systolic pressure (PASP) on echocardiography. Although pulmonary arterial vasodilators may often be considered in this setting, these drugs have been predominantly tested in the subset of PH patients with pulmonary arterial hypertension (PAH). Elevated PASP alone is not sufficient for the diagnosis of PAH, and secondary causes of PASP elevation, most commonly left heart disease, are far more prevalent than isolated PAH. Treatment of this more common group of patients with PH due to left heart disease is challenging because there are few evidence-based treatment options, and pulmonary vasodilator therapy may lead to worsening symptoms. Therefore, improving symptoms and avoiding adverse outcomes in patients with PH requires the following: (1) understanding the optimal use of echocardiography for the diagnosis of PH; (2) recognizing the utility and proper interpretation of invasive hemodynamic testing prior to starting pulmonary vasodilator therapy; (3) differentiating PAH from pulmonary venous hypertension due to left heart disease; and (4) understanding the appropriate treatment strategies for PH and resultant right heart failure.