Pulmonary hypertension (PH) is a complex and severe medical condition characterized by elevated blood pressure in the pulmonary arteries, leading to significant morbidity and mortality if untreated. The condition involves multiple pathophysiological mechanisms that can result in right heart failure due to increased resistance in the pulmonary circulation. The World Symposium on Pulmonary Hypertension (WSPH) has developed a comprehensive classification system to facilitate the understanding, diagnosis, and treatment of PH.