Goiter with normal thyroid function

Thyroid tissue has a strong ability to concentrate iodine. The human thyroid gland needs 60--80ug of iodine per day to produce physiologically active thyroid hormones. In the body, the thyroid hormone secreted by the thyroid gland and the pituitary thyroid stimulating hormone (TSH) have an interdependent and mutually-restricted feedback relationship. When iodine deficiency occurs, thyroid cells cannot synthesize sufficient thyroid hormone and the concentration of blood thyroid hormone Decreased, the inhibitory effect of thyroid hormone on pituitary secretion (TSH) weakened, secretion of pituitary TSH increased, TSH levels in blood increased, causing thyroid hypertrophy.