Varicose veins are veins under the skin of the legs, which have become widened, bulging, and twisted. They are very common and do not cause medical problems in most people. There are two main systems of veins in the legs:
Deep veins: The leg muscles squeeze the deep veins during walking, carrying most of the blood back up the legs to the heart.Superficial veins: These occur under the skin which are less important and can form varicose veins.
All of these veins contain one-way valves to ensure that the blood flows towards the heart. Failure of these valves allows blood to flow backwards down the veins and results in an overload of pressure when standing. This excess pressure leads to widening of the veins so that they do not close properly. Blood then flows back into the leg along these veins and causes varicose veins to develop. Raised pressure in these veins also encourages the development of spider veins and discoloured areas which look like bruises.
For many people, there are no symptoms and varicose veins are simply a cosmetic concern. In some cases.