Up to 60% of the adult population will develop varicose veins and/or smaller visible veins called "spider" veins. What causes varicose and spider veins is just beginning to be understood. It is now believed that a type of injury to vein walls and venous valves is the problem. This injury is actually an acquired inflammation of the vein walls and valves. This is in turn exacerbated by other factors such as heredity, obesity, female gender, pregnancy, hormones, standing occupation and aging. Genetics plays a big role in the development of varicose veins. Although it's not possible to change the genes your parents gave you, many other factors also affect the formation and severity of varicose veins.
How Veins Work
To understand why the different lifestyle factors make such an impact, it's important to have a basic understanding of how veins work. The main purpose of leg veins is to return blood up the legs to the heart. The blood is pumped up the legs by muscle contraction and breathing. So, when you walk or move, the venous blood moves. And when you stand still, so does the blood.
The weight of all the blood in your legs is very heavy - so heavy, in fact, you would think it would drain down to your feet when you stand still. The veins prevent this from happening. Hundreds of small valves within the leg veins shut when you stand still. These valves keep the blood in place and stop it from running back down to your feet. When you start to walk again, the valves open up and the blood is pumped toward the heart. More about varicose vein treatments ...