Varicose veins are tortuous, twisted, or lengthened veins. Unless the enlargement is severe, size alone does not indicate abnormality because size can vary depending on ambient temperature and, in women, hormonal factors. In addition, normal superficial veins in a thin person may appear large, whereas varicose veins in an obese person may be hidden. Varicose veins can be classified as trunk, reticular, or telangiectasia. Telangiectasia are also referred to as spider veins, star bursts, thread veins, or matted veins. Most varicose veins are primary; only the minority are secondary to conditions such as deep vein thrombosis and occlusion, pelvic tumours, or arteriovenous fistulae.