Causes of Hypothyroidism
Primary |
Autoimmune hypothyroidism: Hashimoto's thyroiditis, atrophic thyroiditis |
Iatrogenic: 131I treatment, subtotal or total thyroidectomy, external irradiation of neck for lymphoma or cancer |
Drugs: iodine excess (including iodine-containing contrast media and amiodarone), lithium, antithyroid drugs, p-aminosalicylic acid, interferon α and other cytokines, aminoglutethimide, sunitinib |
Congenital hypothyroidism: absent or ectopic thyroid gland, dyshormonogenesis, TSH-R mutation |
Iodine deficiency |
Infiltrative disorders: amyloidosis, sarcoidosis, hemochromatosis, scleroderma, cystinosis, Riedel's thyroiditis |
Overexpression of type 3 deiodinase in infantile hemangioma |
Transient |
Silent thyroiditis, including postpartum thyroiditis |
Subacute thyroiditis |
Withdrawal of thyroxine treatment in individuals with an intact thyroid |
After 131I treatment or subtotal thyroidectomy for Graves' disease |
Secondary |
Hypopituitarism: tumors, pituitary surgery or irradiation, infiltrative disorders, Sheehan's syndrome, trauma, genetic forms of combined pituitary hormone deficiencies |
Isolated TSH deficiency or inactivity |
Bexarotene treatment |
Hypothalamic disease: tumors, trauma, infiltrative disorders, idiopathic |
Abbreviations: TSH, thyroid-stimulating hormone; TSH-R, TSH receptor.