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Griffin Bullock


  • Low TSH and High T4 and/or T3 (primary): Graves’ disease, Toxic goiter, TSH-producing adenoma, hyperemesis gravidarum, subacute granulomatous thyroiditis, amiodarone, radiation, excessive replacement, struma ovarii

  • Low TSH/Normal T4 and T3: Subclinical hyperthyroidism, central hypothyroidism, non-thyroidal illness, recovery from hyperthyroidism, pregnancy (physiologic)

  • Subclinical Hyperthyroidism: repeat testing to verify abnormality is not transient


  • Anxiety, emotional lability, heat intolerance, tremor, palpitations, increased appetite, unexplained weight loss, new onset atrial fibrillation, myopathy, menstrual disorder, exophthalmos, tachycardia, pretibial myxedema, hyperreflexia, lid lag, changes to hair or skin


  • TSH, free T4, free T3 (only T3 or T4 may be elevated, though both often are)

  • Biotin affects assay, causes falsely ↓ TSH and falsely ↑ FT4/FT3

  • CBC: May have a normocytic anemia due to increased plasma volume


  • Thyrotropin antibodies (Graves-specific test, not sensitive)

  • Radioiodine uptake scan if thyrotropin antibodies negative

    • Note: if pt has had a contrasted study wtih radioactive iodine in the past 6 weeks, the RAI update scan will not be helpful
  • Treatment: methimazole, PTU, beta blockers, radioiodine ablation, surgery

  • Pts should be referred to endocrinology for treatment plan based on work up

Last update: 2022-06-20 11:12:21