Thyroid Hormone Test - Triiodothyronine - T3

This test measures the blood levels of triiodothyronine, a thyroid hormone.

This test measures the blood levels of triiodothyronine, a thyroid hormone.

This test checks the blood level of T3 (triiodothyronine), a hormone made by the thyroid gland. It is often done along with or after a thyroid-stimulating hormone (TSH) test and thyroxine (T4) test.

  • Thyroid hormones help control how the body uses energy, but are also associated with managing body temperature, muscle function, heart rates, and mental functioning.
  • This test may be done with other thyroid tests to see how well your thyroid gland is working.

In an adult, the blood sample is taken from a vein in the arm. If this test is done on an infant, blood is collected by pricking the heel or finger.

  • Some medications can interfere with the test. Ask your healthcare provider if you need to stop taking any medications before the test.
  • Do not stop taking any medication unless your healthcare provider tells you to do so.

What should I ask my healthcare provider before having this test?

  • Is there any special preparation for the test? (If so, get clear instructions on what you need to do.)
  • What is the reason for the test? Will the test results change my treatment plan? If not, do I need the test?


Also known as:

Thyroid Hormone Test - Triiodothyronine - T3
Thyroid Gland
Thyroid Function
Thyroid Blood Test
T3 Blood Test
Laboratory Work
Hypothyroid Test
Hyperthyroid Test
Blood Test for Thyroid Disorder helps consumers determine the average cost of common medical procedures in their location. By gathering and analyzing data from leading insurance providers across the US, patients can compare the estimated price of common medical procedures to determine their approximate out-of-pocket expenses. All rates are approximations and not guarantees based on data that is available to the consumer. There are currently 638 procedures available in our database. These results and the information contained within should in no way take the place of actual medical advice.

Do not avoid getting health care based on the information on this site. Not affiliated with any insurance provider, hospital, or medical professional. Prices are just estimates based on available data, and may vary based on plan, state, and provider. For informational purposes only.