Triiodothyronine, Reverse (rT3)

Analyte [material]

Triiodothyronine, reverse (rT₃) [S/P]

Reference range, target level, or decision threshold

0.1-0.3 microg/L (0.15-0.45 nmol/L)

Interpretation of results

↑ Severe nonthyroid diseases (may be elevated or within the reference interval), Graves disease (adult and neonatal), thyroid hormone resistance, thyroid-stimulating hormone (TSH)-dependent hyperthyroidism, subacute thyroiditis (elevated)

↓ Primary hypothyroidism, transient neonatal hypothyroidism, Hashimoto thyroiditis, TSH deficiency

rT₃ is used to differentiate between central hypothyroidism and sick euthyroid.