Pulmonary hypertension (PH) is a disease that is generally first encountered by primary care physicians. Usually, patients present with dyspnea on exertion and a loss of exercise tolerance, although they can have symptoms of chest discomfort, syncope, or edema. Most patients are diagnosed with 2-dimensional Doppler echocardiography although echo is not 100% sensitive or specific in making this diagnosis. Note that the diagnostic criteria for this disease have changed recently. Most patients develop PH secondary to left heart failure, or to pulmonary disease with or without hypoxemia. Ultimately, many patients require right heart catheterization for diagnosis and for proper treatment. This is best performed by those that specialize in management of this disease. It is important to diagnose patients who have PH due to pulmonary artery hypertension and patients with chronic thromboembolic PH as these patients require specialized treatment that is most effective if started early in the disease course. This review discusses issues related to diagnosis and appropriate referral of patients with PH.