- The state produced by excessive quantities of endogenous or exogenous thyroid hormone. [thyro- + G. toxikon, poison, + -osis, condition]- apathetic t. chronic t., presenting as cardiac disease or as a wasting syndrome, with weakness of proximal muscles and depression but with few of the more typical clinical manifestations of t..- t. medicamentosa a hyperthyroid state resulting from excessive doses of thyroid hormone preparation.
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* * *n.the syndrome due to excessive amounts of thyroid hormones in the bloodstream, causing a rapid heartbeat, sweating, tremor, anxiety, increased appetite, loss of weight, and intolerance of heat. Causes include simple overactivity of the gland, a hormone-secreting benign tumour or carcinoma of the thyroid, and Graves's disease (exophthalmic goitre), in which there are additional symptoms including swelling of the neck (goitre) due to enlargement of the gland and protrusion of the eyes (exophthalmos). Treatment may be by surgical removal of the thyroid gland, radioactive iodine therapy to destroy part of the gland, or by the use of drugs (such as carbimazole or propylthiouracil) that interfere with the production of thyroid hormones.• thyrotoxic adj.
* * *thy·ro·tox·i·co·sis (thi″ro-tok″sĭ-koґsis) the condition caused by excessive quantities of thyroid hormones (see hyperthyroidism); it may be due to overproduction by the thyroid gland as in Graves disease, overproduction originating outside the thyroid, or loss of storage function and leakage from the gland.
Medical dictionary. 2011.