Injection treatment is by far the most usual. It is both cosmetic and effective. The veins are injected where they bulge with sclerosant, which acts like glue to make the two sides stick together and stay sealed at the injection point; this means the blood flow is automatically diverted to travel through other veins.
Surgical treatment, or 'stripping', is normally carried out in severe conditions. A fine wire is inserted and the vein is literally stripped out and removed. Usually, stripping is done on two or three main veins, often the entire length from ankle to groin and sometimes shorter lengths above the knee. Always look for an expensive surgeon.