Spider veins are close to the skins surface and may look thin and wispy like spider webs or thick and squiggly like branches. They are similar to varicose veins, only thinner. Although we tend to think of spider veins as a cosmetic problem, many times there is an underlying medical cause that has created the spider veins. If you have spider veins along with any other symptom of vein disease (stinging, throbbing, aching, numbness, etc.) then you may have an underlying issue. An evaluation and an ultrasound test can establish if spider veins are cosmetic in nature or a result of venous insufficiency.