Heart valve disease occurs when one or more of the four heart valves do not function properly. These valves control blood flow through the heart and ensure it moves in the right direction. When valves become narrowed (stenosis) or leak (regurgitation), it can lead to various symptoms, including fatigue, shortness of breath, and swelling in the legs. Diagnosis typically involves echocardiograms and other imaging tests to assess valve function. Treatment options may include medication, lifestyle changes, or surgical procedures to repair or replace the affected valves, helping to restore normal blood flow and improve overall heart health.