Heart valve diseases occur when one or more of the four heart valves do not function properly. These valves, which include the aortic valve, mitral valve, pulmonary valve, and tricuspid valve, help regulate blood flow through the heart. 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 physical exams, echocardiograms, and other imaging tests. Treatment options vary based on the severity of the disease and may include medications, lifestyle changes, or surgical procedures to repair or replace the affected valve.