“Spider veins” or “star bursts” are the small pink, red or purple surface veins that appear on thighs, lower legs and ankles. Caused by dysfunctional valves within the vessels, the star-burst effect may develop due to pregnancy, hormone replacement therapy, oral contraceptives, obesity, trauma or heredity. Sclerotherapy is an outpatient procedure involving an injection that can improve the appearance of -- or entirely eliminate -- surface veins. A hypertonic saline or Sotradecol solution is injected into the dilated blood vessels, causing them to swell and close. Most individuals feel only a brief “mosquito bite” type of sting during the procedure. Since blood vessels are interconnected, one injection may eradicate several dozen vessels at once. As the injection fluid coats the inner walls of the blood vessels, they will shrink and slowly disappear from the surface of the skin. Small spider veins may vanish completely over a period of six to eight weeks following treatment, and larger veins will decrease in size. The incidence of serious side effects is rare. Post-treatment swelling normally lasts no more than 24 hours. Any local bruising that develops will fade within a few weeks. Individuals with a history of vascular problems such as thrombophlebitis, blood clots or ulcers in the legs should not receive sclerotherapy. Alternative treatments are available.