Unexplained dyspnea may have many causes, which is why patients must have a complete diagnostic work-up to rule out pulmonary hypertension (PH) as a root cause. The differential diagnosis of PH is multifaceted and should be a collaborative effort between the community healthcare provider and the PH specialist at the PH center. Many diagnostic evaluations may be performed outside of the PH center, but right heart catheterization, which is the definitive procedure, and adjoining tests should be performed at the center. Newer and emerging diagnostic imaging techniques may also prove helpful, particularly in diagnosing chronic thromboembolism leading to chronic thromboembolic pulmonary hypertension. This program reviews the diagnostic approach to determining whether PH is the root cause of patients’ dyspnea and considers when community physicians, having created an index of suspicion for PH, should immediately refer their patients to the PH center for a full work-up.