Varicose veins are caused by enlarged or tangled veins, typically in the legs and upper thighs. The condition is about twice as prevalent in women, and the current consensus is that varicose veins are caused by increased blood pressure and muscle abnormalities around the affected veins. Varicose veins can be aggravated by pregnancy, obesity, constipation, leg injuries and leg surgery. Elderly individuals are at greatest risk of developing varicose veins. Symptoms can be eased by elevating the legs while sitting or lying down, and frequent walking. Medical interventions include laser and chemical treatments designed to reduce venous inflammation and swelling.