Excess iodine refers to excessive iodine intake, which may lead to goiter, hyperthyroidism (e.g. fear of heat, excessive sweating, diarrhea, weight loss), hypothyroidism (e.g. fatigue, chills, memory loss), etc. 1. Goiter: excessive intake of high iodine food, excessive iodine into the body will inhibit the activity of thyroid peroxides, inducing compensatory enlargement of the thyroid gland. 2. Hyperthyroidism: Excessive iodine intake may lead to iodine hyperthyroidism, which may be manifested as fear of heat, excessive sweating, diarrhea and weight loss. 3. Hashimoto’s thyroiditis: Excessive iodine intake may induce Hashimoto’s thyroiditis, which causes symptoms of hypothyroidism (such as fatigue, chills, memory loss, etc.). Although iodine is an essential substance for the human body, excessive iodine will bring harm to health, and normal people are recommended to eat a moderate iodine diet.