Sclerotherapy is the injection of medication (“sclerosant”) via a needle into small superficial veins or "spider veins". The goal is to irritate and scar the veins from the inside such that these abnormal veins close and no longer fill with blood. Doing so instantly and permanently reduces unsightly veins.
There is little to no risk from sclerotherapy for small veins and groups of veins. For insurance reasons...
Sclerotherapy significantly reduces the appearance of veins but due to genetics, hormones, sun exposure, and aging the development of new small superficial veins can occur.