In the past 2 decades, major changes have occurred in the epidemiological and treatment landscape of pulmonary arterial hypertension (PAH). Previously regarded as a disease of the young and middle-aged, contemporary registries from the Western world have demonstrated an increase in the age of patients with PAH, many of whom are elderly with multiple comorbidities. Another important observation is the improvement in survival of patients with PAH in the modern treatment era compared with historical cohorts, before the availability of advanced therapy. The management of PAH has also become more complex, and numerous drugs are now approved that target the endothelin 1, nitric oxide, and prostacyclin pathways. Combining drugs from different classes is now considered the standard of care and has been demonstrated to improve outcomes. Furthermore, the current treatment paradigm is the early use of combination therapy, often at the time of diagnosis, particularly in patients with severe disease. This Review provides a comprehensive update on the epidemiology and pharmacotherapy of PAH.