What is valve disease?

Heart valve problems: The heart also has four valves: the tricuspid, pulmonary, mitral, and aortic valves. These valves open and close, acting like doors in the heart, making sure that blood flows correctly from the atria into the ventricles, and then from the ventricles to the rest of the body. Valves can become too leaky, allowing blood to flow backwards, or too narrowed, preventing blood from leaving a chamber.

If you are referring: to the heart then it can be a stenotic (minimal movement due to calciific deposits) or a reugitant valve where the valve, instead of being only a one way valve becomes a two way valve thereby allowing blood to flow backwards as well as forward.