131 iodine is an important method of treating adult hyperthyroidism, which has the advantages of convenient treatment, high cure rate, few side effects and low recurrence rate. Before choosing radioactive iodine treatment, you need to pay attention to the following aspects: 1, low iodine diet. Before treatment (preferably within one month), it is forbidden to eat seafood (kelp, nori, marine fish, shrimp, crab, etc.), and freshwater fish can be eaten normally. 2, choose radioactive iodine treatment of hyperthyroidism before to stop taking anti-hyperthyroidism drugs, such as Sage, Tabazole, PTU or contains anti-hyperthyroidism components of proprietary Chinese medicines, stopping time according to the length of personal use of medication and the amount of medication can be adjusted slightly, generally stopping the drug half a month or so has been able to significantly reduce the impact of the drug on the radioactive iodine treatment before the examination and treatment, the specific time to stop the drug can be consulted to consult the consultation department. 3. It is recommended to bring the previous examination results, especially the thyroid function test; 4. Do not hide the complications associated with hyperthyroidism or the history of chronic diseases that may affect the treatment, such as diabetes mellitus.