Spider veins are sometimes called thread veins and the technical word is telangiectasia. These are the very fine red vessels that are less than 1mm in diameter and develop on the legs, face, chest and neck. They are often fed by larger and slightly deeper blue straight veins called reticular veins. Spider veins and reticular veins are flat, not raised like varicose veins. Spider veins are new veins that have grown in the skin whereas varicose veins are veins which have always been there but have become dilated (stretched up and bulging) and tortuous (windy or twisted) due to high pressure in the superficial venous system.
Winter is often the time to think about having spider veins treated. That way, when summer arrives, the treatment has been completed and one does not have to wear stockings during the summer heat.