Hyperthyroidism, as the name implies, means that the thyroid gland synthesizes excessive amounts of thyroid hormones. Iodine is the basic raw material for the synthesis of thyroid hormones. In order to reduce the synthesis of hormones at the source, it is necessary to avoid iodine diet, including abstaining from iodine-rich foods and medications. The first category contains thousands to tens of thousands of micrograms of iodine, including kelp, nori, moss, jellyfish, etc. The second category contains hundreds to thousands of micrograms of iodine, including sea crab, mussels, shrimp, etc. The third category contains tens to hundreds of micrograms of iodine, including sea fish, shrimp, etc. In addition, you should use “non-iodized salt” when cooking for hyperthyroidism (you can buy it from the local salt company after getting a certificate from the hospital) and try to reduce the number of meals out. 3. Avoid using drugs with high iodine. Amiodarone, iodine, and vitamins containing iodine, lozenges and contrast media are prohibited. Cosmetics containing seaweed ingredients, such as facial cleansers and face masks, should also be avoided. After hyperthyroidism is cured, excessive iodine intake may easily lead to recurrence of hyperthyroidism, so excessive consumption of high iodine food in a short period of time should be avoided.