Varicose veins are swollen, twisted veins that sit close to the surface of the skin—most commonly in the legs. They happen when the tiny valves inside your veins stop working properly, allowing blood to flow backwards and pool. For some people they’re mainly a cosmetic concern; for others they can cause aching, heaviness, swelling, skin changes, and complications that need treatment. What are varicose veins? Your veins carry blood back to your heart. In the legs, they’re work