Pulmonary valve disease occurs when the pulmonary valve between the right ventricle and pulmonary artery does not function properly. There are several types of pulmonary valve disease including pulmonary stenosis where the valve is narrowed, reducing blood flow to the lungs, and pulmonary regurgitation where the valve leaks, allowing blood to flow backward into the right ventricle. The diseases can cause symptoms such as shortness of breath and fatigue. Treatment depends on the type and severity, ranging from monitoring to surgical procedures to repair or replace the valve.