Pulmonary valve disease occurs when the pulmonary valve between the right ventricle and pulmonary artery does not function properly. This can interrupt blood flow from the heart to the lungs. Pulmonary valve stenosis and regurgitation are two types of pulmonary valve disease. Pulmonary valve stenosis involves a narrowing of the valve that reduces blood flow, while regurgitation occurs when the valve leaflets do not close tightly, causing blood to leak back into the right ventricle. The severity of symptoms depends on the type and severity of pulmonary valve disease. Treatment options may include procedures to repair or replace the pulmonary valve.