Veins are the vessels in the body that send oxygen rich blood out into the body and bring oxygen-poor blood back from the capillaries to the heart and lungs for oxygenation. Veins are relatively thin-walled so that they collapse more readily than arteries and so can break down more readily into varicose veins than arteries. Knowing what causes varicose veins is the first step in getting rid of them and preventing their occurrence in the first place.
Varicose veins look like thick, ropy purple or blue veins occurring most commonly on the legs, thighs and calves. These are areas under the most pressure when you stand or sit for long periods of time. Varicose veins are common, affecting 19 percent of men and 36 percent of women. There appears to be a hereditary component to getting varicose veins, which is one cause of varicose veins. Varicose veins tend to be superficial veins and are highly visible when they become enlarged. Blood tends to travel from the superficial veins to the deep veins and, when the valves inside the veins get damaged, blood backs up and puts pressure on the vein walls.
There are many causes of varicose veins in the legs. Damaged valves inside the superficial veins of the legs are the most common cause of varicose veins. Valves keep blood flowing in the direction toward the heart and prevent blood from going backwards in the veins. When the valves become damaged due to excess pressure, they fail to keep the blood flowing forward and it leaks back into the previous vein segment. This results in more pressure in that vein segment and it begins to expand. Eventually, the dilatation becomes permanent and the valves stay leaky and blood just pools in the veins.
Some doctors believe that some people have a hereditary predisposition to have too few valves in the veins. Alternatively, you can be born with weak connective tissue in the valves. This means you get varicose veins much earlier in life than normal people. The older you get, the more likely it is to have had years of excess venous pressure behind you and you get varicose veins.
You can be born with connective tissue abnormalities of the wall of the vein. This makes the wall more distensible so it dilates early in life. If you have a job that requires that you stand for long periods of time, this only makes varicose veins worse. Even healthy people without hereditary problems with their veins can have varicose veins from prolonged standing at home or at the workplace.
Muscles that are too strong in the area of the deep veins can contribute to varicose veins. Since the veins travel from superficial to deep veins, the excess pressure in the deep veins can cause back up in the superficial veins. Blood travels backwards and you get superficial varicose veins.
Many factors can aggravate the situation. Pregnancy can cause varicose veins. There is more blood flowing through the body in pregnancy and this adds pressure to the veins of the legs and abdomen. The growing uterus puts pressure on deep veins which backs up into the superficial veins. It is made worse if you have to stand a lot during pregnancy. Obesity can do the same thing. Even people who strain because of urinary retention or chronic constipation can get varicose veins. See your doctor if you have either of these conditions