Free Thyroxine Index

The Free Thyroxine Index (FTI) is a calculation used to assess thyroid function by estimating the amount of free, or unbound, thyroxine (T4) in the blood. It combines the results of the total T4 test and the thyroid hormone-binding ratio (THBR) to account for changes in proteins that bind thyroid hormones, providing a more accurate picture of thyroid activity. The FTI is commonly used to diagnose and monitor conditions like hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid).

Test Details:

Sample Type: Serum	Tube Type: SST
Collection Method: In person at a Lab location	Results: 1-6 days from sample arrival at our lab
Age: 18+