Heart valve disease comes in many forms and can be genetic, a birth defect, or can be caused by illness or heart disease. Mitral valve prolapse, mitral valve regurgitation, and aortic valve stenosis are just some of the common heart valve problems. Heart murmurs are usually harmless and are caused by blood flow through heart valves. Sometimes though, heart murmurs are caused when a heart valve is damaged, either due to a heart defect from birth or heart disease. Follow the links below to find WebMD's comprehensive coverage about how heart valve problems & murmurs are caused, diagnosed, treated, and much more.