Hyperthyroidism is a common endocrine disease with an incidence rate of about 2% in China. The incidence ratio of male to female hyperthyroidism is 1:6, and 80% of the patients are young and middle-aged women. Anti-thyroid drugs, radioactive iodine-131 and surgery are the three recognized treatments for hyperthyroidism at home and abroad. If you see other treatments for hyperthyroidism on the Internet (especially on the top recommended websites of some search engines) or in newspapers, such as Chinese medicine, immune balancing treatment, nanotechnology treatment, etc., they are mostly unreliable and please pay attention to screening. Surgery is rarely used nowadays because it may lead to serious complications such as damage to the parathyroid glands and the recurrent laryngeal nerve. Anti-thyroid medication is the most common treatment for hyperthyroidism, especially for mild to moderate hyperthyroidism in the first episode. The course of medication is usually one and a half to two years, and patients need to follow up regularly according to their doctors’ requirements and standardize the medication. If medication is not effective, relapses after stopping medication or develops allergy, leukopenia, or impaired liver function, radioactive iodine therapy is recommended. However, for patients older than 40 years old with complications such as cardiac insufficiency, liver damage or leukopenia, radioactive iodine treatment can be directly selected. Since the first case of hyperthyroidism was treated with radioactive iodine-131 in 1942, 2 million hyperthyroid patients have been treated with iodine-131 worldwide, and more than 200,000 hyperthyroid patients have been treated with iodine-131 in China so far. A large number of clinical applications at home and abroad have proved that radioactive iodine-131 treatment for hyperthyroidism is the most mature and widely used method of radionuclide therapy because of its simplicity, safety, precise efficacy, low recurrence rate, few complications and low cost. However, most patients with hyperthyroidism know little about radioactive iodine-131 treatment for hyperthyroidism, or there are certain misconceptions about this treatment method. I have summarized the following questions of patients in clinical practice. First, patients do not know that there is radioactive iodine-131 treatment for hyperthyroidism. Some patients with hyperthyroidism, especially those from remote rural areas, are surprised to learn that there are treatments for hyperthyroidism other than drugs when they finally come to the nuclear medicine department. Some patients told me that in many hospitals they had seen before, the doctors had never mentioned that there was such a method, and when their attending physicians were at their wits’ end in controlling the patient’s condition, they actually told the patients that you could not see this disease. This indicates that although radioactive iodine-131 treatment for hyperthyroidism has been carried out in China for decades, due to the uneven distribution of medical conditions, this effective treatment for hyperthyroidism is not routinely carried out in the central and western regions and in the first and second level hospitals below the third level, and primary care physicians lack a certain level of awareness of this treatment. These patients come to the nuclear medicine department to seek hyperthyroidism treatment either by mistake or through the introduction of their hometown or relatives and friends, and they all have the attitude of trying it out. I am often asked by patients whether radioactive iodine-131 treatment is nuclear radiation, whether it is very toxic, whether they will lose their hair after using it, whether they will never be able to get pregnant again, and so on. After radioactive iodine-131 reaches the thyroid gland, it can emit γ and β rays during the decay process, and the main therapeutic effect is β rays. Because beta rays have a shorter range, 1 mm on average and 2.2 mm at the longest, they can destroy the thyroid tissue but have little or no effect on the tissues and organs around the thyroid, and do not cause hair loss, leukemia, cancer and other side effects. Of course, there is a part of the γ-ray has a long range, does not play a therapeutic role, but will cause a certain amount of radiation to the surrounding population, although the dose is also very low, but in order to reduce unnecessary radiation to healthy people, within a month after taking the drug should be as far as possible to maintain a certain distance from the surrounding population, especially pregnant women and children, do not hug and close contact; conditions permit, it is best to live alone If possible, it is best to live alone, use separate household items, flush the toilet with water several times after urination and defecation, etc. It is also important to note that women with hyperthyroidism during pregnancy and breastfeeding should not receive radioactive iodine-131 treatment because the fetal thyroid gland can concentrate radioactive iodine-131 after 10 weeks of gestation and cause fetal goiter and hypothyroidism. Contraception should also be used for 6 months after choosing radioactive iodine treatment, and it is considered safe to plan a pregnancy after 6 months. Thirdly, radioactive iodine-131 treatment for hyperthyroidism is considered to be a one-time treatment, i.e., a complete cure at once. For radioactive iodine-131 treatment for hyperthyroidism, most of them take the drug at once, while a few may take multiple doses and just follow up regularly after taking the drug, but this does not mean that all patients can be completely cured of hyperthyroidism at once. The cure rate of hyperthyroidism treated with radioactive iodine-131 may vary from hospital to hospital, usually the chance of cure is 70-80%, which means that 20-30% of patients still need a second time, and a few need a third time or more, depending on the patient’s medical history, the type of medication used in previous treatment, the size and texture of the thyroid gland (hard or soft), and the presence of nodules. However, in either case, the ultimate cure rate for hyperthyroidism with radioactive iodine-131 is still close to 100%. In addition, radioactive iodine-131 treatment for hyperthyroidism also has a certain chance of recurrence, even some patients who have been hypothyroid and have been taking thyroxine for a period of time may still have a recurrence of hyperthyroidism, but the recurrence rate is usually less than 10%, which is much lower than that of drug treatment, and the recurrence can still be treated with radioactive iodine-131 again. Fourthly, regarding the age of the patients, in the past, it was thought that adolescents or children with hyperthyroidism were not suitable for radioactive iodine-131 treatment, and this concern might be due to the concern of deformation and cancer caused by radioactive substances, but with the widespread implementation of radioactive iodine-131 worldwide and the long-term follow-up after radioactive iodine-131 treatment for hyperthyroidism in the younger age groups, this concern has been ruled out. Age is no longer considered as an indication or contraindication for radioactive iodine-131 treatment in the guidelines for the treatment of hyperthyroidism, both domestically and internationally. In children or adolescents with hyperthyroidism, as in adults, treatment with radioactive iodine-131 is recommended in cases of poor treatment with antithyroid drugs, allergy, leukopenia or liver damage, in order to minimize the complications of hyperthyroidism and the impact on the growth and development of the child. Finally, about the problem of hypothyroidism after radioactive iodine-131 treatment. Another important reason why many patients have concerns about the use of radioactive iodine-131 is hypothyroidism. Patients often ask questions such as whether hypothyroidism will definitely occur with isotope treatment, whether they have heard that hypothyroidism is terrible, that they will gain weight, lose their hair, that they cannot have children, whether they will have to take medication for the rest of their lives after hypothyroidism, and so on. Iodine-131 treatment for hyperthyroidism not only causes hypothyroidism, but also other treatments (such as medical medication and surgical treatment) may cause hypothyroidism. Some patients with hyperthyroidism may even develop hypothyroidism in the future even if they are not treated. The current consensus of experts in endocrinology and nuclear medicine is that hypothyroidism will occur sooner or later with radioactive iodine-131 treatment of hyperthyroidism, and that hypothyroidism is a sign of cure for hyperthyroidism. The ideal state of curing hyperthyroidism by radioactive iodine-131 without hypothyroidism does not exist. The typical symptoms of hypothyroidism include fatigue, drowsiness, poor memory, mental retardation, unresponsiveness, mild anemia, weight gain, etc. The treatment of hypothyroidism is much simpler than that of hyperthyroidism, i.e., daily thyroid hormone replacement therapy, and the commonly used levothyroxine tablets (trade name Eugenol or Raltez) are very safe and individualized to correct the discomfort of hypothyroidism without producing It can be used individually to correct the discomfort of hypothyroidism without causing toxic side effects. Of course, most patients need to take medication for life after hypothyroidism.