When you sit or stand for long periods, high blood pressure inside the veins in your legs can cause varicose veins. Other factors that can increase your risk for varicose veins:
Deep Vein Thrombosis
Family history of varicose veins
Lack of exercise
Varicose veins affect people between the ages of 30 and 70, with a larger percentage of woman than men. Pregnant women have an increased risk, but the veins often return to normal within one year of childbirth. Multiple pregnancies may result in permanent varicose veins.