Why are women more prone to varicose veins than men are?
Pregnancy is the main reason, most commonly due to increased pressure from the expanding uterus directly against the main veins that drain the legs. In some women the veins become inflamed during pregnancy, most often due to increased pressure from the uterus on the main veins that drain the legs. Increased levels of progesterone during pregnancy and also around the time of menstruation cause the blood vessels to relax. Venous dilation begins in the first trimester of pregnancy due to hormonal changes. Dilation of the vein wall may produce valvular incompetence, or leaking. The impairment or reduction of venous return from the legs increases within months of pregnancy and combined with increased blood volume due to pregnancy and increased weight and size of the uterus, all contribute to swelling in the legs, discomfort in the legs, and formation of varicose veins.
