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adv. Thyroid Panel


TSH, T3, T4, free T3, freeT4

  • TSH

    Diagnosis of hyper- and hypothyroidism.

  • T4 Total, Total thyroxine, serum

    Total thyroxine is rarely measured, having been largely superseded by free thyroxine tests. Total thyroxine (Total T4) is generally elevated in hyperthyroidism and decreased in hypothyroidism.[2] It is usually slightly elevated in pregnancy secondary to increased levels of thyroid binding globulin (TBG).[2]

    Total T4 is measured to see the bound and unbound levels of T4. The total T4 is less useful in cases where there could be protein abnormalities. The total T4 is less accurate due to the large amount of T4 that is bound. The total T3 is measured in clinical practice since the T3 has decreased amount that is bound as compared to T4.

    Reference ranges depend on the method of analysis. Results should always be interpreted using the range from the laboratory that performed the test

  • T3, serum

    Triiodothyronine Total

  • Free T3, Serum

    Evaluation of hyperthyroidism, thyrotoxicosis

  • Free T4, Serum

    Confirming hyperthyroidism; Evaluation of thyroid function in patients with TBG alternations