Pulmonary hypertension can be an independent disease, a complication, or a syndrome. The diagnostic criteria are right heart catheterization at resting state at sea level, and the mean pressure of pulmonary hypertension is greater than or equal to 25 mm Hg. The clinical manifestations of pulmonary hypertension are dyspnea, fatigue, weakness, syncope, angina, even hemoptysis, hoarseness, right heart failure and other symptoms. Right ventricular overload hypertrophy, right atrial dilatation, chest X-ray can indicate the transverse diameter of right lower pulmonary artery greater than or equal to 15 mm, echocardiography can also measure pulmonary hypertension, high-resolution CT and enhanced CT can also understand the width and value of right lower pulmonary artery trunk pressure. Cardiopulmonary exercise test can also understand cardiac function, gas exchange capacity, and pulmonary angiography can further rule out the presence of pulmonary embolism, pulmonary artery tumor, etc. To diagnose pulmonary hypertension, we first identify people at risk for pulmonary hypertension, including various heart diseases and thrombotic diseases. Patients with pulmonary hypertension can be screened by echocardiography, and the diagnosis is further confirmed by right ventricular catheterization for pulmonary hypertension.