(THY-royd STIM-yoo-LAY-ting HOR-mone)
A hormone produced by the pituitary gland. Thyroid-stimulating hormone stimulates the release of thyroid hormone from thyroglobulin. It also stimulates the growth of thyroid follicular cells. An abnormal thyroid-stimulating hormone level may mean that the thyroid hormonal regulation system is out of control, usually as a result of a benign condition (hyperthyroidism or hypothyroidism). Also called TSH.