In order to eradicate the disease, many patients are very willing to undergo Iodine-131 treatment, but they are hesitant about whether the legendary radiation “atomic bomb” will destroy the cancer cells as well as the healthy cells in their bodies. Can their bodies withstand this seemingly powerful treatment? How serious are the side effects of Iodine-131 treatment? Will the treatment endanger family members? Will the patient’s reproductive function be affected after treatment? In fact, iodine-131 treatment is a very safe and reliable treatment method, and the side effects are by no means as terrible as the legend says. Although Iodine-131 is a radioactive treatment drug, the side effects of this treatment are far less than those of radiotherapy and chemotherapy, and do not cause serious vomiting, hair loss, hematuria and other toxic side effects. Studies have shown that iodine-131 itself releases a small amount of gamma rays, and because of its small amount of radiation, it will not adversely affect the patient’s future marriage or fertility, nor will it enhance the probability of tumors in other areas. During the treatment, patients generally have only some mild gastrointestinal reactions, neck swelling and parotid gland swelling, etc. Most of them will be relieved on their own, while some patients with serious reactions can be relieved after symptomatic treatment, which will not affect their daily life and work in any way.