Sclerotherapy is an injection treatment used to eliminate "spider" veins and small to medium-size varicose veins. A solution is injected into the problem vein with a very fine needle. The vein wall becomes irritated. Subsequent application of external compression with dressings and prescription-gradient compression hose seals the vein wall together. The body breaks down the damaged vein and absorbs it, ultimately eliminating the problem vein. No pre-treatment patient preparation is needed and most patients describe minimal discomfort. After treatment patients resume normal activities, but are asked to avoid prolonged sitting and standing for 3 days and heavy exercise (weight lifting, running and high impact aerobics) for two weeks. Walking is encouraged after the treatments. Prescription-gradient compression hose are worn for 9 days after each treatment.