FTI stands for the Free Thyroxine Index and it is an estimation of the free T4 concentration. It is sometimes referred to as T7. It is a calculated value determined from the total T4 test and some estimation of the level of thyroid hormone binding proteins. The original test for estimating the level of binding proteins was called the T3-uptake test and later versions were called T-uptake methods. These are rarely used now that there are methods available to measure free T4 and T3 directly.
3. Are there things that I can do to raise or lower my free T4 level?
In general, free T4 does not respond to lifestyle changes. What is important is that the thyroid gland is producing adequate amounts of free T4 and the body's feedback mechanism is responding appropriately. For those who do not produce enough free T4, thyroid hormone replacement medication can be given.
This article was last reviewed on October 16, 2014. | This article was last modified on June 6, 2016.
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