The word "varicose" means a dilatation and therefore varicose veins are dilated veins. In the simplest cases, varicose veins can be seen as bulging veins in the legs when the patient is standing up. When lying down, the vein is empty and they 'disappear'. These veins are often blue or green if they are close to the skin's surface, although they can be skin coloured if they are deep and have a good covering of skin.