A vein is a blood vessel that carries blood low in oxygen content from the body to the lungs and heart. It is a normal part of the circulatory system. Thousands of people every year consider getting treatment for varicose veins and spider veins. Advertisements for treating venous disease often tout "unique," "permanent," "painless," or "absolutely safe" methods - making it difficult to decide on the best treatment. If you are considering this procedure, the following information may help.