Pulmonary hypertension (PH) is a complex cardiovascular disorder characterized by elevated mean pulmonary artery pressure >20 mmHg at rest. PH is classified into five groups based on etiology, each with unique underlying causes and pathophysiological mechanisms: pulmonary arterial hypertension (PAH), PH due to left heart disease, PH due to lung disease or hypoxia, chronic thromboembolic pulmonary hypertension (CTEPH), and PH with unclear multifactorial mechanisms.