Thyroid Hormone Test - Total Thyroxine - T4

This blood test measures the level of one of the hormones made by the thyroid gland, total thyroxine (T4).

This blood test measures the level of one of the hormones made by the thyroid gland, total thyroxine (T4).

This blood test measures the level of total thyroxine, or T4. T4 is one of the hormones made by the thyroid gland. It is often done along with a thyroid-stimulating hormone (TSH) and triiodothyronine (T3) test to see how well your thyroid gland is working.

  • Thyroid hormones help control how the body uses energy. They are also associated with managing body temperature, muscle function, heart rates and mental functioning.
  • It is a common screening test in newborns.

In an adult, the blood sample is taken by placing a needle in a vein in the arm. In a newborn, the sample is taken by pricking the baby's heel.

  • Be sure to tell your healthcare provider about any medications you are taking.
  • Some medications can interfere with the test.

This care path's costs do not include the charge to draw blood from a vein (venipuncture). There will only be one charge to draw blood, even if multiple tests are being performed on the samples that are taken.

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 - Total Thyroxine - T4
Laboratory Work
Thyroid Blood Test
Low Thyroid
Thyroid Hormone Test - Thyroxine - T4
Blood Test for Thyroid Disorder
Hyperthyroid Test
Hypothyroid Test
Thyroid Function
Thyroid Gland
T4 Blood Test 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.

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