Pulmonary hypertension (PH) is a heterogeneous condition defined by an increase in mean pulmonary arterial pressure over 20 mm Hg diagnosed through right heart catheterization. Its global prevalence is around 0.6% to 1%. The prognosis used to be poor but nowadays early diagnosis, risk stratification, and a personalized treatment can significantly enhance the prognosis and quality of life of these patients. PH pathophysiology comprises genetic and environmental factors, such as endothelial dysfunction, smooth muscle cell proliferation, inflammation, thrombosis, and right ventricular remodeling. Especially in pulmonary arterial hypertension, treatment options have been radically altered.