One noon, Ms. Luo called me. She is 27 years old, married and childless, and has been suffering from hyperthyroidism for 3 years, but has been taking anti-thyroid medication. She had heard that radioactive iodine treatment was very effective, but some people said that people who had not yet had children should not take it, saying that it would make them sterile for life. Indecisive, she called for advice. After I talked with her for half an hour, she immediately made an appointment for me to give her radioactive iodine treatment. In my daily work, I often encounter various questions from patients or their family members, and one of the most frequently asked questions is whether the treatment of hyperthyroidism with radioactive iodine will affect fertility. My answer is definitely not. I once had a patient in her 40s who had a successful pregnancy after radioactive spot treatment. However, many people did not fully understand and accept it, and some of them expressed doubts. Only after I fully explained the rationale, they accepted it sincerely. Oral iodine is absorbed into the bloodstream via the gastrointestinal tract and is rapidly taken up by the thyroid tissue with the blood circulation. The beta rays emitted by iodine kill some of the thyroid cells, causing the thyroid to shrink. This results in a decrease in thyroid hormone synthesis by the thyroid gland, causing the clinical signs and symptoms of hyperthyroidism to disappear. Because 131 iodine is highly selectively taken up and concentrated in the thyroid tissue, the amount of 131 iodine taken up by the thyroid gland per unit weight is hundreds to thousands of times higher than the amount in the blood of normal tissue. The maximum range of beta radiation emitted by 131 iodine is only 2.2 mm, and the average range is 1 mm. Therefore, beta radiation has a strong therapeutic effect on the thyroid gland with minimal effect on surrounding tissues and other organs. By individualizing and optimizing the patient’s treatment dose through the thyroid iodine function test and the condition of the thyroid patient, the oral one-time cure rate is as high as 80%, and there is no impact on health, let alone damage to the reproductive system. Some scholars have investigated a large number of women in their reproductive years who received radioactive iodine treatment, and the incidence of infertility is not different from natural infertility and genetic diseases. It has been proved by domestic and foreign data for decades that fertility is not affected by radioactive iodine treatment for hyperthyroidism, and the children born are healthy, so there is no need to worry about the effect of radioactive iodine treatment on fertility. The main contraindication is pregnancy and lactating women. The reason is that radioactive iodine taken during pregnancy and lactation may damage the thyroid gland of the fetus and infants, causing hypothyroidism. If hypothyroidism occurs after radioactive iodine treatment, thyroid hormone replacement therapy can be used, which will not affect fertility or produce malformations while maintaining a balanced state of thyroid hormone levels in the body. Treatment of hyperthyroidism using radioactive iodine is one of the easiest and most effective methods of treatment for hyperthyroidism recognized worldwide. It is usually an oral solution and usually requires only 1-2 treatments to cure. When former U.S. President George W. Bush suffered from hyperthyroidism during his administration, he was finally treated with this method after consultation and discussion by many world-class authoritative medical experts, and received good results. Patients with hyperthyroidism are more suitable for radioactive iodine treatment especially for those who have long duration of the disease, recurrent relapses, thick neck, complications or contraindications and cannot adhere to the medication. As long as the dosage is chosen appropriately, the efficacy is much better than that of drug therapy, and the side effects are not significant. Patients do not need to be hospitalized, the total cost is low, and the recurrence rate is also low. Both foreign physicians and patients tend to use isotopes as the first choice for hyperthyroidism treatment. At present, some western countries have included this as the preferred method, and 70% of patients choose this method to treat hyperthyroidism. Since 1996, the People’s Hospital has been treating hyperthyroidism with radioactive iodine, and every year, it treats hundreds of patients with hyperthyroidism with radioactive iodine. This method of treating hyperthyroidism is painless without any surgery, and the course of treatment is short, without long-term medication, with a low recurrence rate, which is economical and convenient, so that hyperthyroidism patients do not have to go to Guangzhou, Zhuhai and other major cities to queue up for medical treatment.