Thyrotoxicosis: clinical and laboratory assessment.

Thyroid hormones are triiodothyronine (T3) and thyroxine (T4). The hypophysial thyrotropic hormone, thyroid stimulating hormone (TSH) is their physiologic regulator. Thyrotoxicosis is characterized by clinical symptoms caused by high thyroid hormone concentrations. The commonest forms are: 1) toxic diffuse goiter (Basedow-Flajani-Graves disease), 2) toxic multinodular goiter, 3) toxic adenoma. Other less frequent forms are the iodide-induced, that during Hashimoto thyroiditis, that from inappropriate TSH secretion. The diagnosis is predominantly clinical and confirmed by hormone level determination associated in some cases to functional and morphofunctional tests (TRH test, scintigraphy, thyroid I uptake) and antithyroid antibody assay.