Pulmonary arterial hypertension is a rare condition that requires a thorough workup to evaluate for potential causes and right heart catheterization for definitive diagnosis and decision-making about treatment options. JAMA Associate Editor Kristin Walter, MD, MS, discusses the recent JAMA review article titled “Pulmonary Arterial Hypertension Classification, Diagnosis, and Treatment” with one of the authors, Nicole Ruopp, MD, assistant professor of medicine at Tufts Medical Center and Tufts University School of Medicine. Related Content: Diagnosis and Treatment of Pulmonary Arterial Hypertension