How Spider Veins Appear on Your Body Spider veins are formed by the dilation of a small group of blood vessels located close to the surface of the skin. Although they can appear anywhere on the body, spider veins are most commonly found on the face and legs, particularly on the thighs, calves and ankles. Visit at http://www.veinsweb.com/spider-veins-sclerotherapy.php for more details. in Public bookmarkswith sclerotherapy-spider-veinsby 7 users