Hypothyroidism may be caused by

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: Hoshimoto's 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, Riedel's 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 Grave's 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 TSH, thyroid-stimulating hormone; TSH-R, TSH receptor.