Alternate Names : Venous Varicosities
Normally, tiny one-way valves inside each vein keep blood from flowing backward. When valves are damaged or do not work properly, a vein may start to bulge and twist. This is called a varicose vein.
What is going on in the body?
After blood filled with oxygen is pumped through the body, veins bring oxygen-depleted blood back to the heart. Normally, one-way valves inside veins keep gravity from pulling the blood toward the feet. When valves are not normal or have been damaged, blood pools in the vein. The kinks, bulges, and lumps of varicose veins then occur. Varicose veins are most often noticed on the thigh or calf, where they are close enough to the skin to be seen. Varicose veins can, however, occur in other parts of the body.
What are the causes and risks of the condition?
The cause of this disorder is failure of the valves in the veins to prevent the backward flow of blood. The following conditions increase the risk of this condition:
a family history of this condition
occupations where people stand or sit most of the time
Women are much more prone to varicose veins than men. In fact, one in two women develop varicose veins. This has been linked to changes in hormones that women experience at puberty, during pregnancy, and at menopause.
A woman is more likely to get varicose veins:
if she takes estrogen or progesterone in birth control pills or estrogen replacement therapy
during the first trimester of pregnancy as the uterus expands and more weight is put on the legs. When this occurs during a woman's first pregnancy, these veins often disappear when the baby is born. That may not happen with later pregnancies.
A permanent condition known as milk leg may sometimes occur during pregnancy. It happens when valves in the veins have been destroyed and the pressure of the pooled blood causes swelling.