Thyroid-Stimulating Hormone (TSH)

Thyrotropin, TSH (Thyroid-Stimulating Hormone)

What To Think About

• The thyroid-stimulating hormone (TSH) test is the best screening test for conditions that can affect the thyroid gland.
• The results of a TSH test should be considered along with the results of thyroid hormone tests, especially thyroxine (T4) results. For more information about T3 and T4 testing, see the medical test Thyroid Hormone Tests.
• Another test that measures TSH levels in the blood is called the thyrotropin-releasing hormone (TRH) challenge test. TSH blood levels are measured before and after an injection of TRH. Normally the injection causes the pituitary gland to release TSH. TSH levels that do not rise after the injection can indicate the presence of conditions such as a damaged pituitary gland (secondary hypothyroidism), Graves' disease, or any condition that causes an overactive thyroid gland (hyperthyroidism).
• The upper value of the normal TSH range for adults is 4.5 mIU/L or 4.5 mU/L (SI units).

Go to previous section	Go to top of page	Go to next section
Author:	Sydney Youngerman-Cole, RN, BSN, RNC	Last Updated: July 26, 2006
Medical Review:	Caroline S. Rhoads, MD - Internal Medicine Matthew I. Kim, MD - Endocrinology & Metabolism
© 1995-2008 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.