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Medical Term:


Pronunciation: thi'ro-tok'sin


  1. A hypothetic substance formerly believed to be an abnormal product of diffusely hyperplastic thyroid glands in people with Graves disease, and presumed to cause the distinctive signs and symptoms of that condition (in contrast to simple hyperthyroidism).
  2. A complement-fixing antigenic factor associated with certain diseases of the thyroid gland.
  3. Rarely used term referring to any material toxic to thyroidal tissue.
© Copyright 2017 Wolters Kluwer. All Rights Reserved. Review Date: Sep 19, 2016.