Iodine 131 treatment is a type of radiotherapy that can be used for the treatment of hyperthyroidism, thyroid cancer and other diseases. Iodine 131 is an artificial radionuclide. Iodine 131 treatment makes use of the highly selective uptake of iodine by human thyroid tissues, and achieves its therapeutic purpose by taking radioactive iodine ions, which destroy the cells of thyroid tissues and reduce the production of thyroid hormones. Patients with hyperthyroidism or after surgery for thyroid cancer can be treated with Iodine 131 under the supervision of a physician. Note that iodine 131 is contraindicated for treatment during pregnancy and lactation. Iodine 131 treatment should be carried out in regular medical institutions to avoid the adverse effects caused by irregular operation.