Causes Of Thyrotoxicosis

Causes of thyrotoxicosis A.Primary hyperthyroidism 1) Graves' disease 2) Toxic multinodular goiter 3) Toxic adenoma 4) Functioning thyroid carcinoma metastases

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Activating mutation of the TSH receptor

Activating mutation of Gsα (McCune-Albright syndrome) 7) Struma ovarii 8) Drugs: iodine excess (Jod-Basedow phenomenon) B. Secondary hyperthyroidism 1) TSH-secreting pituitary adenoma

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Thyroid hormone resistance syndrome: occasional patients may have features of thyrotoxicosis HCG-secreting tumors

Gestational thyrotoxicosis C. Thyrotoxicosis without hyperthyroidism 1) Sub acute thyroiditis 2) Silent thyroiditis 3) Other causes of thyroid destruction: amiodarone, radiation, infarction of adenoma 4) Ingestion of excess thyroid hormone (thyrotoxicosis factitia) Nb. Circulating TSH levels are low in these forms of secondary hyperthyroidism.

Causes of Hypothyroidism A.Primary Hypothyroidism 1) Autoimmune hypothyroidism:  Hashimoto's thyroiditis

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Atrophic thyroiditis

Drugs: iodine excess (including iodine-containing contrast media) Amiodarone Lithium Anti-thyroid drugs

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p-aminosalicyclic acid interferon-α other cytokines, aminoglutethimide

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Iatrogenic:

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I treatment Subtotal or total thyroidectomy

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External irradiation of neck for lymphoma or cancer Congenital hypothyroidism absent or ectopic thyroid gland dyshormonogenesis TSH-R mutation Infiltrative disorders  Amyloidosis  Sarcoidosis  Hemochromatosis

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Scleroderma  Cystinosis  Riedel's thyroiditi Iodine deficiency

Overexpression of type 3 deoiodinase in infantile hemangioma 8) Transient 9) Silent thyroiditis, including postpartum thyroiditis 10) Subacute thyroiditis 11) Withdrawal of thyroxine treatment in individuals with an intact thyroid B.Secondary Hypothyroidism 1) Hypopituitarism: tumors, pituitary surgery or irradiation, infiltrative disorders, Sheehan's syndrome, trauma, genetic forms of combined pituitary hormone deficiencies 2) Isolated TSH deficiency or inactivity 3) Bexarotene treatment 4) Hypothalamic disease: tumors, trauma, infiltrative disorders, idiopathic