Pulmonary arterial hypertension (, PAH) is one of the types of pulmonary hypertension (PH). Other types of pulmonary hypertension include: pulmonary hypertension due to left heart disease; pulmonary hypertension due to lung disease and/or hypoxia; chronic thromboembolic pulmonary hypertension; pulmonary hypertension of unknown cause and/or due to multiple factors (e.g., hematologic disease, systemic disease, metabolic disease and neoplastic obstruction, fibromediastinitis). The diagnostic criteria for pulmonary hypertension (PH) are: mean pulmonary artery pressure ≥ 25 mmHg measured by right heart catheterization at rest. pulmonary arterial hypertension (PAH) is defined as mean pulmonary artery pressure ≥ 25 mmHg measured by right heart catheterization at rest, along with pulmonary capillary wedge pressure (PCWP) ≤ 15 mmHg. pulmonary hypertension includes the following categories: 1. idiopathic pulmonary hypertension; 2. hereditary pulmonary hypertension; 3. drug- and toxin-induced pulmonary hypertension; 4. disease-related pulmonary hypertension (connective tissue disease, HIV infection, portal hypertension, congenital heart disease, schistosomiasis); 5. pulmonary veno-occlusive disease and/or pulmonary capillary hemangiomatosis; 6. persistent pulmonary hypertension in newborns. The previously so-called primary pulmonary hypertension and familial pulmonary hypertension have been replaced by idiopathic pulmonary hypertension and heritable pulmonary hypertension. In recent years, significant progress has been made in the treatment of pulmonary hypertension. A number of targeted therapeutic agents not only significantly improve patients’ activity tolerance, but also extend life expectancy. Current drugs with clear efficacy include prostacyclin analogs, endothelin receptor antagonists, and 5-type phosphodiesterase inhibitors. They are mainly used for idiopathic pulmonary hypertension, hereditary pulmonary hypertension, pulmonary hypertension due to weight loss drugs, pulmonary hypertension associated with connective tissue disease and pulmonary hypertension associated with congenital heart disease. Other treatments include improvement of right heart failure symptoms, such as digoxin, diuretics; oxygen; warfarin anticoagulation therapy and calcium antagonists. Calcium antagonists are only effective in patients with idiopathic pulmonary hypertension and heritable pulmonary hypertension who have a positive pulmonary vasodilator test; avoid blind use without a pulmonary vasodilator test to avoid worsening of the disease. Only about 10% of patients with idiopathic pulmonary hypertension are sensitive to calcium antagonists. However, the acute pulmonary vasodilatation test should be repeated after one year of use, and continued use should be allowed only if the test is still positive. In advanced cases, heart and lung transplantation is performed. Currently, targeted therapy drugs are expensive. It is believed that with the continuous progress of science and technology, the continuous development of new drugs, and the deepening competition among manufacturers, the price will gradually decrease, so that more patients can benefit. The above therapeutic advances are mainly aimed at the first major category of pulmonary arterial hypertension (PAH); pulmonary hypertension caused by left heart disease has the primary goal of treating the original disease; pulmonary hypertension caused by lung disease and/or hypoxemia also has no specific treatment. Oxygen therapy may delay the progression of COPD-related pulmonary hypertension. The use of conventional vasodilators is not recommended and may impair gas exchange; the specific treatment for chronic thromboembolic pulmonary hypertension is pulmonary artery endothelial dissection. Targeted drug therapy can be tried for those who are inoperable, for preoperative preparation for surgery, or for postoperative relapse. It is well established that amirex, fenfluramine, dexfenfluramine, and toxic rapeseed oil are associated with pulmonary arterial hypertension (PAH); tryptophan, levotryptophan, and methamphetamine are very likely to be associated with PAH; other than that, the mechanism of most PAH is unknown, making targeted prevention difficult. The following patients are at high risk of pulmonary hypertension and should undergo cardiac ultrasound every 6 months or 1 year for early detection and treatment: 1, first-degree relatives with idiopathic pulmonary hypertension and heritable pulmonary hypertension; 2, patients with connective tissue disease; 3, cirrhosis combined with portal hypertension; 4, congenital heart disease with body-pulmonary circulation shunt; 5, thyroid disease; 6, patients with chronic pulmonary embolism.