Sclerotherapy destroys abnormal and unsightly veins. At times, blood is trapped within segments of those veins and needs to be removed to minimize the development of pigmentation after treatment. Sclerotherapy really does not produce blood clots and the trapped blood is NOT dangerous and does not travel. If sclerotherapy is not performed properly with the correct concentration of solution and the use of medical graduated compression stockings after treatment, blood clots can occur. This, fortunately, is extremely rare. Seeking professional help from a board certified dermatologist who is experienced in sclerotherapy treatment will greatly reduce your chances of experiencing any adverse effects following sclerotherapy. For more information, it's a good idea to schedule a consultation with a doctor to gain a better understanding of the treatment.