Varicose veins are dilated (enlarged) superficial veins. They can occur in any area of the body surface, but they are primarily a problem in the legs. There are several causes for the dilatation that occurs in superficial veins. Primary varicose veins are a result of gradual degeneration in the valves within the veins. These valves occur at regular intervals along the course of the veins. The valves permit blood to flow toward the heart and restrict the ability of blood to flow away from the heart and into the veins. These valves prevent the development of high pressure within leg veins even when one is standing.
