<prompt> Hypothyroidism may be caused byLithiumHematochromatosisSclerodermaAll of the above  <response>: Answer is D All of the above: Hypothyroidism may be caused by drugs like Lithium and or Infiltrative disorders like Scleroderma and Hematochromatosis. Causes of Hypothyroidism Causes of Hy pothyroidism Primary Autoimmune hypothyroidism: Hoshimotos thyroiditis, atrophic thyroiditis Iatrogenic: 1311treatment, 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-a and other cytokines, aminoglutethimide Congenital hypothyroidism: absent or ectopic thyroid gland, dyshormogenesis, TSH-R mutation Iodine deficiency Infiltrative disorders: amyloidosis, sarcoidosis, hemochromatosis, scleroderma, cystinosis, Riedels thyroiditis Overexpression of type 3 deoiodinase in infantile hemangioma Transient Silent thyroiditis, including postpaum thyroiditis Subacute thyroiditis Withdrawal of thyroxine treatment in individuals with an intact thyroid After 1311 treatment or subtotal thyroidectomy for Graves disease Secondary Hypopituitarism: tumors, pituitary surgery or irradiation, infiltrative disorders, Sheehans syndrome, trauma, genetic forms of combined pituitary hormone deficiencies Isolated TSH deficiency or inactivity Bexarotene treatment Hypothalamic disease: tumors, trauma, infiltrative disorders, idiopathic TSH, thyroid-stimulating hormone; TSH-R, TSH receptor. 