The Scientist: Ted King, M.D., Vice President of Medical Affairs of Vein Clinics of America and a practicing phlebologist in Oakbrook Terrace, IL.The Answer: Another old wives’ tale put to rest! Crossing your legs absolutely does not cause varicose veins. They are hereditary—and that’s that.A significant portion of adults (some studies say 20 to 25 percent of men and women) get varicose veins—those twisted veins that seem to bulge out of your legs. If you’re stuck with them, what’s happened is that the walls of your veins have lost elasticity, so they aren’t able to stretch and relax the way they’re supposed to. Genetic damage also causes the veins to become stiffer, so once they’re stretched out, they can’t shrink back down.Another aspect is that the valves inside the veins that keep blood flowing in the right direction stop working. That means blood can no longer move upward, against gravity. Instead, it falls downward and pools within your veins, further stretching them out. Fortunately, varicose veins are superficial blood vessels, which are responsible for only 10 to 20 percent of the total blood flow out of your legs, so it doesn’t cut off supply to vital organs. Plus, when you lie down at night, your blood flows in the right direction, even through bad veins.There’s nothing you can do to prevent varicose veins—if you’ve got the gene, they will follow. The same goes for spider veins, which are just tiny varicose viens. If you have them and want to treat them, see a phlebologist (vein specialist) to ask about options including ablation (a quick procedure in which the larger vein above affected vessels is sealed with a laser) and removing the bulging veins themselves. For help finding a physician, go to ON VARICOSE VEINS FROM YOUBEAUTY.COMThe Best Treatments for Varicose VeinsOlympian Summer Sanders Talks about Her Varicose VeinsVideo: Pregnancy and Varicose Veins