The pulmonary valve is located between the right ventricle and the pulmonary artery, and is the gateway between the right ventricle and the pulmonary artery. Pulmonary regurgitation is commonly caused by two reasons. First, high pressure in the pulmonary circulation causes some blood to break through the pulmonary valve into the right ventricle due to high pressure. This type of disease is commonly associated with pulmonary stasis and chronic obstructive pulmonary disease, and usually requires a chest CT examination and cardiac ultrasound to assist in the diagnosis. Second, pulmonary valve insufficiency, in the end of right ventricular systole, when the pressure in the right ventricle is less than the pressure in the pulmonary artery, some blood will enter the right ventricle through the pulmonary valve. If the degree is mild, there is usually no need for deliberate treatment, but if the patient has been combined with significant heart failure and other symptoms, valve replacement surgery is required for treatment.