(See also Overview of the Venous System Overview of the Venous System Veins return blood to the heart from all the organs of the body. The large veins parallel the large arteries and often share the same name, but the pathways of the venous system are more difficult... read more .)
Spider veins (also called telangiectasia) are small veins that become enlarged and are visible under the skin.
Photo courtesy of Robert S. Porter, MD.
Although spider veins usually do not cause symptoms, many people consider even the smallest spider veins unsightly.
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Many people with or without varicose veins Varicose Veins Varicose veins are abnormally enlarged superficial veins in the legs. Varicose veins may ache or cause itching or a sensation of tiredness. Doctors can detect varicose veins by examining the... read more 
may have spider veins, which are enlarged capillaries. Capillaries are tiny, extremely thin-walled vessels that act as a bridge between arteries (which carry blood away from the heart) and veins Overview of the Venous System Veins return blood to the heart from all the organs of the body. The large veins parallel the large arteries and often share the same name, but the pathways of the venous system are more difficult... read more (which carry blood back to the heart).
Spider veins may be caused by the pressure from blood in varicose veins, but the cause is generally thought to be hormonal factors that are not yet understood. A hormonal cause would explain why spider veins most commonly occur in women, particularly during pregnancy.
Spider veins usually cause no symptoms. Some people do have pain or burning. Many people consider spider veins unsightly. Doctors recognize spider veins by their appearance. Tests are not needed.
Treatment of Spider Veins
Injection therapy (sclerotherapy)
Spider veins can usually be eliminated by injection therapy Injection therapy (sclerotherapy) Varicose veins are abnormally enlarged superficial veins in the legs. Varicose veins may ache or cause itching or a sensation of tiredness. Doctors can detect varicose veins by examining the... read more (sclerotherapy) similar to that done for varicose veins Varicose Veins Varicose veins are abnormally enlarged superficial veins in the legs. Varicose veins may ache or cause itching or a sensation of tiredness. Doctors can detect varicose veins by examining the... read more . In sclerotherapy, a solution, such as sodium tetradecyl sulfate, is injected into each of the spider veins to irritate them and produce a blood clot that blocks them. Large areas of spider veins (multiple telangiectasias) may require several treatments because the injections are painful. The skin may darken, but this discoloration usually subsides, often completely.
Laser treatment is also effective, but large areas require several treatments. This therapy uses a laser beam to destroy the small veins.
Small spider veins may persist or recur after initial treatment.
