Iodine-131 treatment is a kind of radionuclide treatment, and the X-rays and gamma rays it produces will cause radioactive contamination of the surrounding environment. Therefore, it is necessary to isolate patients undergoing iodine-131 treatment and set up a radiation isolation zone for them. Patients themselves should pay attention to avoid contact with pregnant women and infants, and communicate with others at least one meter apart, and the contact time should be as short as possible. That is, short contact time and long contact distance. Radioactive Iodine-131 side effects are common in the digestive tract and urinary system. Iodine-131 that is absorbed by the body tends to be excreted in the feces. Therefore, patients usually drink more water and excrete more. Dietary attention should be paid to eating more food that can be easily digested. The hospitals are very considerate to these patients, and there are usually separate bathrooms in the wards. The bedding of patients is usually treated with special equipment for radioactive decay.