Thyroid Blood Tests
There are numerous thyroid tests that can be done in order to evaluate the functioning of your thyroid gland. The tests below are those that have been recommended as a starting point for evaluating thyroid function. If you suspect that you have a thyroid problem but have been previously told that your thyroid is “normal”, you may want to make sure that the following tests have been done and then get a copy of your test results for your own review.

TSH – Thyroid Stimulating Hormone
The TSH test is the most common type of blood test that physicians order however, it does not provide the “full picture” in terms of thyroid health. Measuring the amount of thyroid stimulating hormone (TSH) in your bloodstream, the TSH test is just one test used in thyroid hormone testing.

Free T3 – Total Triiodothyronine
T3 is the name for Triiodothyronine and by getting the “FREE” T3 test, you are measuring the amount of active thyroid hormone in your system.

Free T4 – Total Thyroxine/Serum Thyroxine
The “Free” T4 tests measures the levels of unbound, free thyroxine levels in your blood. Conversely, bound levels of the hormone are levels of the hormone that are circulating but not available immediately to the body for it’s use and can be affected by illness, other drugs or pregnancy. Because the “FREE” T3 levels are measuring hormone levels of immediately available hormones, it is thought to be a better test than the Total T4 levels.

TPO – Thyroid Peroxidase (TPO) Antibodies (TPOAb) / Antithyroid Peroxidase Antibodies
This test is very important because TPO antibodies, if you have them, make your body work against thyroid peroxidase, which is important in the body’s ability to convert T4 to T3. Having TPO antibodies can also be a sign of tissue destruction and Hashimotos Disease, and may also make your other thyroid tests (TSH) etc, fluctuate between being normal, too high, or too low, depending if when the tests were done, your thyroid gland was being attacked by the thyroid antibodies. Many women have been told that their thyroid’s were “fine” without being tested for TPO antibodies and later found out that they had undiagnosed Hashimotos Disease which contributed to a problem with feeling poorly for years because they were never tested for thyroid antibodies.

Thyroglobulin/Tg
Antithyroglobulin antibodies or TG antibodies may also be a sign of Hashimotos disease or Graves Disease. Graves Disease patients with Thyroglobulin antibodies may be more likely to eventually become hypothyroid at some point in the future.

It is a good idea to always get copies of all your lab work and keep those in a folder so that you can begin monitoring your own results. When test results come back keep in mind that you will be given a “range” of what is normal for each specific test. It is important to look at your “range” and note or discuss any high or low ranges with your doctor if you are not feeling well. For example, the rangs for TSH is generally 0.3 to 3.0 but if someone has results in the 2.9 range, then they may not feel optimal at that level. What you will be learning is to find out not only what your results are, but to advocate for yourself so that you can determine where you feel “optimal”.