Pulmonary arterial hypertension is defined as a mean pulmonary arterial pressure greater than 25 mm Hg at rest or 30 mm Hg during physical activity. Pulmonary arterial hypertension is classified into subgroups, including idiopathic, heritable, and pulmonary arterial hypertension associated with other conditions. A detailed history, thorough physical examination, and most importantly, a high index of suspicion are essential to diagnosis. Evaluation includes echocardiography and exclusion of other causes of symptoms. Targeted laboratory testing can help identify the subgroup of pulmonary arterial hypertension. Right heart catheterization is required to confirm the diagnosis. Standard treatment options include oral anticoagulation, diuretics, oxygen supplementation, and for a small percentage of patients, calcium channel blockers. Newer treatments include prostacyclin analogues, endothelin receptor antagonists, and phosphodiesterase type 5 inhibitors. Combination therapy has been shown to improve pulmonary arterial pressure, but more research is needed. Interventional procedures for patients with pulmonary arterial hypertension include balloon atrial septostomy and lung transplantation.