In clinical practice, it is not uncommon for patients to worry about the occurrence of hypothyroidism and to be reluctant to receive iodine-131 treatment, which delays their condition. At this time, it is very important for primary care doctors to educate their patients that the chance of early onset hypothyroidism is about 10%, and even if hypothyroidism occurs, as long as they insist on regular follow-up and medical treatment, early detection and early treatment can be achieved. As long as thyroxine replacement therapy is taken in time, patients can live a healthy life as normal people and will not affect their normal life and fertility. At the same time, the age of treatment is also a concern for patients. Primary care physicians should explain to patients that a large number of clinical practices at home and abroad have proved that iodine-131 is safe and effective in treating hyperthyroidism in adolescents and children. Although the available data indicate that iodine-131 is not carcinogenic in the treatment of hyperthyroidism, further evaluation of the potential long-term risks is necessary because of the long follow-up period for pediatric and adolescent patients and the limited data available on long-term (60-70 years) follow-up studies after iodine-131 treatment. Targeted population Most scholars believe that iodine-131 therapy can be used for adolescent and pediatric patients who are allergic to antithyroid drugs, or who are poorly treated with thyroid drugs, or who have significant toxic side effects, or who have relapsed after treatment with antithyroid drugs, or who have a more pronounced enlarged thyroid gland. For hyperthyroidism combined with liver dysfunction, antithyroid drugs may further aggravate liver damage. Metabolic disorders in the body due to hyperthyroidism are one of the causes of liver dysfunction, and timely control of hyperthyroidism is necessary to prevent recovery of liver function. In contrast, iodine-131 treatment should be the best choice. Timing of treatment The absorbed dose of bone marrow at the dose of iodine-131 treatment is extremely small and does not cause changes in white blood cells. If the patient’s white blood cells are not lower than 3.0×109/L, he can be treated directly with iodine-131. If the patient’s white blood cells are below 3.0×109/L, it is recommended that Iodine-131 treatment be considered after appropriate “leukostasis” measures have been taken. The dose of iodine-131 is influenced by many factors and should be increased in the following patients: 1) obvious enlargement and hard texture of the thyroid gland; 2) nodular goiter; 3) long medical history; 4) poor efficacy of long-term antithyroid drugs; 5) short effective half-life; 6) elderly patients; 7) positive TSH receptor antibodies; 8) patients with no significant effect of the first iodine-131 treatment; 9) patients with poor sensitivity to iodine-131. 9. Patients with poor sensitivity to iodine-131. On the contrary, if the enlargement of the thyroid gland is not obvious, if the disease is short, if the disease is mild, if the patient has not been treated with antithyroid drugs, if the effective half-life is long, if the patient is young, if the patient has recurrence of hyperthyroidism after surgery, and if the patient has not been cured after the first treatment with iodine-131, the dose of iodine-131 should be reduced appropriately. Time to effect Treatment of hyperthyroidism with iodine-131 is currently recognized as an effective method worldwide and has been adopted as the preferred method in some western countries. Most patients can be controlled after iodine-131 treatment and can be cured with a single dose, while a few patients require a second or even multiple treatments. It usually takes 2 to 6 weeks after taking iodine-131 for the effect to begin, with gradual improvement of symptoms within 3 months and total elimination of symptoms within 6 months to 2 years. Symptomatic treatment For hyperthyroidism patients taking iodine-131 treatment, doctors have to communicate with patients in advance that the effect is relatively slow (2~6 weeks) and that patients’ symptoms will not improve or may even worsen early after treatment, which is related to the amount of thyroid accumulation in the body. Therefore, it is also important to take effective symptomatic treatment with a combination of Chinese and Western medicine during this period. After treatment Chromosomal variants are rarely observed in hyperthyroidism patients after iodine-131 treatment, and if there are variants that are only transient, they mostly return to normal. Patients with infertility or sterility or sexual dysfunction due to hyperthyroidism will have their fertility and sexual function significantly restored after iodine-131 treatment as their hyperthyroidism is controlled. There have been no reports of elevated fetal malformations due to hyperthyroidism treated with iodine-131. Studies have shown that it is safe to get pregnant after six months of iodine-131 treatment. It is worth mentioning that regular monitoring of serum thyroid function indicators is needed after treatment, and timely detection of hypothyroidism and replacement therapy is also crucial.