Iodine-131: Iodine-131 is a radionuclide that emits beta and gamma rays, of which the therapeutic effect is beta rays. It is taken orally and absorbed into the bloodstream by the stomach and intestines, so that the active thyroid tissue can take in large quantities and actively “synthesize” thyroid hormone during hyperthyroidism. Since the range of beta radiation is only a few millimeters, it does not have a destructive effect on the surrounding tissues and organs. At present, the international treatment status of hyperthyroidism is that iodine 131 is preferred in Europe and the United States. The domestic treatment situation is that internal drug treatment is dominant, but in large medical institutions, the proportion of iodine 131 treatment is higher and even dominates. The academic circles at home and abroad agree that iodine 131 treatment is preferred for hyperthyroidism in the elderly. The indications for iodine 131 treatment of hyperthyroidism in the latest Clinical Technical Practice of the State Ministry of Health have removed the age restriction in the previous textbook. Adults with hyperthyroidism can be treated with iodine 131. The following conditions are particularly suitable for iodine 131 treatment: 1. Hyperthyroidism combined with reduced white blood cells and platelets, or fatal granulocyte deficiency. 2. Allergy to medical treatment of hyperthyroidism. 3. Hyperthyroidism combined with liver function damage. 4. Moderate or severe hyperthyroidism. 5. Hyperthyroidism combined with periodic paralysis. 6.Hyperthyroidism heart disease. 7.Recurrence of hyperthyroidism after surgery. 8.Women with hyperthyroidism urgently want to get pregnant as soon as possible. 9.Other refractory hyperthyroidism (long duration of the disease, several years to decades of untreated), etc. It is estimated that more than 2 million hyperthyroidism patients worldwide have been treated with iodine 131 over the past 60 years. Statistics from the Nuclear Medicine Branch of the Chinese Medical Association show that in 2009, a total of 171,800 cases of hyperthyroidism were treated with iodine 131 in mainland China, including Hainan Province. Medical studies in Europe, America and China have proved that iodine 131 treatment for hyperthyroidism does not cause sterility and iodine-131 treatment for hyperthyroidism does not lead to an increase in the incidence of malignant tumors, and it is now considered the safest treatment for hyperthyroidism. Treatment of hyperthyroidism with iodine-131 is contraindicated during pregnancy, as it may cause damage to the fetal thyroid gland. Iodine-131 treatment will result in hypothyroidism, which is similar to surgery. Long-term hypothyroidism requires lifelong oral thyroxine, but hypothyroidism is simple to treat and does not affect quality of life, including fertility and longevity, after regular treatment.