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Thyroid Blood Testing

By The Lucy Rose Clinic

March 30, 2020

There are many different blood tests available that aim to measure thyroid function, so which ones do you need?

What tests are available?

TSH: this test, commonly called the TSH, measures the amount of Thyroid Stimulating Hormone present in your blood. The hormone is secreted from the pituitary to signal the thyroid to produce more T4 and T3 thyroid hormones. Reference range: 0.3 -4.5 mlU/L

Free T3: measures the active form of T3 thyroid hormone which is not bound to a protein. This is the thyroid hormone that does all the work in the body and is converted from T4.

Free T4: measures thyroid hormone T4 (not bound to protein) which converts to T3. High T4 can indicate low cellular thyroid function.

Thyroid Antibodies: (TgAB anti thyroglobulin antibody). Looks for these antibodies in your blood as an indication of autoimmune conditions such as Hashimoto’s Thyroiditis or Graves Disease.

Anti-Microsomal Antibody: also called thyroid peroxidase, this is another indication of autoimmunity for Graves (hyper) or Hashimoto’s (hypo).

Reverse T3: measuring Reverse T3 (RT3) can indicate how well T4 is converting to T3. If RT3 is elevated it shows this process is not happening as it should. Reverse T3 blocks the process of Free T3, so if it is high and your T3 is normal you could still show symptoms of hypothyroid as the T3 hormone cannot work effectively.

Relying on just the TSH test, as is standard, means relying on just one measure to determine your health. Without comparison with the other blood tests available, the TSH test can only shown show the amount of the pituitary hormone available in the blood. It is unable to give an indication of how much thyroid hormone is present in the blood and how well it is functioning, whether the thyroid hormones are active or whether there are any antibodies present in the blood. It can’t show if anything else blocking it, if there is poor conversion from T4 to T3, slow manufacture of the hormones, or WHY any of these things are happening.

Our health is too important to rely on only part of the picture! To learn about further testing, just click here to organise a free call with one of our practitioners to discuss which testing is important for your health.


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