BACK
TO
TOP
Browse A-Z

 
E-mail Form
Email Results

 
 
Print-Friendly
Bookmarks
bookmarks-menu

Thyroid function tests

Thyroid function tests are used to check whether your thyroid is working normally.

The most common thyroid function tests are:

  • Free T4 (free thyroxine, the main thyroid hormone in your blood -- a precursor for T3)
  • TSH (thyroid stimulating hormone, the hormone from the pituitary gland that stimulates the thyroid to produce T4)
  • Total T3 (total triiodothyronine, the active form of the hormone -- T4 is converted to T3)

If you are being screened for thyroid disease, often only the TSH test may be needed.

Other thyroid tests include:

  • Total T4 (the free hormone and the hormone bound to carrier proteins)
  • Free T3 (the free active hormone)
  • T3 resin uptake (an older test that is rarely used now)
  • Thyroid uptake and scan
  • Thyroid hormone binding globulin
  • Thyroglobulin
  • Anti-thyroid antibody tests

The vitamin biotin (B7) can affect the results of many thyroid hormone tests. If you take biotin, talk to your health care provider before you have any thyroid function tests.

References

Faix JD. Thyroid function testing (thyrotropin, triiodothyronine, and thyroxine). In: Robertson RP, ed. DeGroot's Endocrinology. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 68.

Guber HA, Oprea M, Rusell YX. Evaluation of endocrine function. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 25.

Pearce EN, Hollenberg AN. Thyroid. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 207.

Salvatore D, Cohen R, Kopp PA, Larsen PR. Thyroid pathophysiology and diagnostic evaluation. In: Melmed S, Auchus RJ, Golfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 11.

Wassner AJ, Smith JR. Thyroid development and physiology. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 579.

  • Thyroid function test - illustration

    One way to evaluate the performance of the thyroid is through blood testing. The thyroid function test is a group of common tests used to evaluate how the thyroid is functioning.

    Thyroid function test

    illustration

  • Thyroid function test - illustration

    One way to evaluate the performance of the thyroid is through blood testing. The thyroid function test is a group of common tests used to evaluate how the thyroid is functioning.

    Thyroid function test

    illustration

A Closer Look

 

Tests for Thyroid function tests

 

St. Luke’s, 915 East First Street, Duluth, MN 55805 218.249.5555 | 800.321.3790

Review Date: 2/28/2024

Reviewed By: Sandeep K. Dhaliwal, MD, board-certified in Diabetes, Endocrinology, and Metabolism, Springfield, VA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
© 1997- adam.com All rights reserved.

 
 
 

 

 

A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.
Content is best viewed in IE9 or above, Firefox and Google Chrome browser.