Thyroid Studies Normal Lab Values

 Thyroid studies are performed if a thyroid disorder is suspected. Common laboratory blood tests such as thyroxine, TSH, T4, and T3 are done to evaluate thyroid function. Thyroid studies help differentiate primary thyroid disease from secondary causes and from abnormalities in thyroxine-binding globulin levels. Thyroid peroxidase antibodies test may be done to identify the presence of autoimmune conditions involving the thyroid gland.

Laboratory Values for Thyroid Function Test

  • Triiodothyronine (T₃): 80 to 230 ng/dL
  • Thyroxine (T₄): 5 to 12 mcg/dL
  • Thyroxine, free (FT₄): 0.8 to 2.4 ng/dL
  • Thyroid-stimulating hormone (thyrotropin): 0.2 to 5.4 microunits/mL

Nursing Considerations

  • Results of the test may be invalid if the client has undergone a radionuclide scan within 7 days before the test.