It is generally believed that iodine-131 treatment for hyperthyroidism has a higher chance of developing hypothyroidism than other treatments (e.g., medical medication, surgical treatment). In this regard, it is important to have a correct understanding. The harm of hyperthyroidism is much higher than that of hypothyroidism, so the main purpose of treatment is to reduce the level of thyroid hormones in the body as soon as possible and alleviate the symptoms. 2, hyperthyroidism (Grave’s disease) is an autoimmune disease, and there are obvious individual differences in disease regression, and a considerable number of hyperthyroid patients may develop hypothyroidism in the future even without treatment. 3. Some scholars believe that the appearance of hypothyroidism is a sign that hyperthyroidism is cured. Compared with hyperthyroidism, hypothyroidism is very easy to treat. It can usually be corrected by taking thyroxine. In other words, thyroxine is artificially supplemented, just like vitamin supplementation for vitamin deficiency in human body. Thus, the level of thyroid hormone in the blood is quickly restored to normal. 5. A reasonable dosage usually does not produce toxic side effects because the supplemented thyroid hormone is inherent and necessary in the human body.