Heart valve disorders occur when one or more of the heart's valves do not function properly, affecting the flow of blood through the heart. The main types include stenosis, where the valve opening is narrowed, and regurgitation, where the valve does not close properly, allowing blood to leak backward. Causes can include congenital heart defects, age-related changes, infections, or other heart conditions. Symptoms may range from fatigue, shortness of breath, and chest pain to swelling in the legs and irregular heartbeats. Treatment varies depending on the severity and type of valve disorder and may involve medications, lifestyle changes, or surgical interventions to repair or replace the affected valve.