If you are a first-time patient, blood tests are usually done to check the level of thyroid hormones in the blood and to determine the 131 iodine absorption rate of the thyroid gland. There are no special requirements for blood sampling, but 131 iodine absorption rate measurement requires fasting on iodine-rich foods such as kelp, nori, scallop, sea cucumber, jellyfish, shrimp and other seafood for 2 to 4 weeks before the test, and discontinuing the use of iodine-containing, bromine-containing, and sedative drugs for one month. In addition, the use of antithyroid drugs, thyroxine and Chinese herbal medicines such as seaweed, kombu, shellfish, mouton, xiakoucao, danshen, forsythia and balsam should be discontinued for 2-4 weeks if they have an effect on the rate of iodine absorption. Fasting is required on the day of the test. The 131 iodine absorption rate test includes both the quantity and speed of iodine absorption by the thyroid gland, so it needs to be observed dynamically and measured at three different times, i.e., one minute 2 hours, 4 hours and 24 hours after the oral 131 iodine intake, which takes two mornings in total, and the result will be released at that time after the 24-hour test. If the patient is a follow-up patient and is currently taking treatment drugs, only blood tests are required, no fasting is required, and the test is usually taken as soon as the patient arrives. However, whether you are taking thyroxine tablets for hypothyroidism or anti-thyroid medications such as Tabazole or Propylthiouracil, you should stop taking them before the blood is drawn on the same day and take them again after the blood is drawn. The results of blood tests will be available roughly once or twice a week, depending on the hospital. For patients with hyperthyroidism treated with radioactive 131 iodine, they should have an empty stomach before the treatment, and take 131 iodine medicine orally for 2 hours before eating. Before and after the treatment, they should pay attention to resting, preventing colds and flu, avoiding overwork and mental stimulation, and eating a diet of high-energy, high-protein, and less oily food, and continue to abstain from iodine-containing foods and medicines, and rinse urine and faeces with water more often for 3 days after taking 131 iodine and have as little contact as possible with or without contact with Infants and young children, another point to note is that we must go to the hospital for regular review and observation of changes in the condition.