The valves of the human heart prevent blood from flowing backwards as it is pumped through the body ensuring healthy blood flow and optimum distribution of oxygen and nutrients throughout the body. However, a number of heart defects affecting the valves can cause problems in the circulatory system and valve repair surgery may be necessary.
There are three basic categories of heart valve problems. In regurgitation also called backflow the valve does not close properly; this allows blood to flow backward through the heart. This happens most often due to the mitral valve folding or pushing out back into the heart chamber. With stenosis, the valve itself begins to thicken or the sides of the valve fuse together. This means that the valve will be unable to open all the way and sufficient blood cannot be pumped through the heart. Atresia, the third condition, occurs when the valve has no opening at all for blood to flow through.