Endocarditis Prophylaxis - University of Chicago

If the serum TSH is lower than 0.1 uU/ml, plasma free T4 and T3 should be measured. If the serum TSH is low, and free T4 and T3 are high, the diagnosis of hyperthyroidism is confirmed, and a 24-hour thyroid radioiodine uptake scan can be ordered to differentiate Grave’ hyperthyroidism from other causes (see p. 461, Lancet article). ................
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