First of all, it is important to know why “iodine solution” (iodine 131) can treat “hyperthyroidism”. “Hyperthyroidism” is the abbreviation for hyperthyroidism. The normal human thyroid gland has the function of secreting (“producing”) thyroid hormones, which regulate the metabolism of various substances in the body, maintain the excitability of the human nervous system, and the needs of growth and development of infants and children. The production of thyroid hormones is essential, and the main raw material is iodine, which is absorbed by the thyroid gland in most cases. When hyperthyroidism occurs, the thyroid gland’s ability to absorb iodine is “out of control”, so it is necessary to curb this “out of control”, which results in the currently used iodine 131 therapy, anti-thyroid drugs and surgical removal of the thyroid gland. This results in the currently used treatments of iodine 131, antithyroid drugs and surgical removal of the thyroid gland. Please refer to my other articles for the advantages and disadvantages of each of these three treatments. Iodine 131 is a radioactive substance that, like the iodine in our food, is involved in the synthesis of thyroid hormones. Thus when the thyroid gland absorbs iodine 131, the radioactivity produced by iodine 131 kills the thyroid cells and reduces the number of thyroid cells, thus treating hyperthyroidism. In the treatment, because the main metabolic site is the thyroid gland, and there is only a transient effect on the liver, kidneys and gonads, iodine 131 treatment does not have an adverse effect on the liver and other organs, but on the contrary, hyperthyroidism over time and medication has the potential effect on liver damage.