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Triiodothyronine (T3) - description and reference ranges

What is it?

Triiodothyronine (T3) is one of two main hormones that is produced by your thyroid. The other hormone is called Thyroxine (T4). Both T3 and T4 work to regulate your metabolism and affect your weight, temperature and nervous system, among others.

T3, T4 and TSH results are frequently used together for the diagnostics of thyroid problems.

Reference ranges

If your indicative T3 level is lower than the reference range for our laboratory:

Low T3 levels may mean you have hypothyroidism, a condition in which your body does not produce enough T3.

You should discuss this result with your GP.

If your indicative T3 level is higher than the reference range for our laboratory:

If your results show high T3 levels, it may mean you have a thyroid condition.

You should discuss this result with your GP.

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