The Free Thyroxine Index (FTI) is a calculated value used to assess thyroid hormone activity in the body. It estimates the amount of biologically active thyroxine (T4) by accounting for variations in thyroid hormone–binding proteins, providing a more accurate reflection of thyroid function than total T4 alone.
This test is commonly used to help evaluate thyroid disorders such as hypothyroidism or hyperthyroidism. It is often ordered alongside other thyroid tests, including TSH and total T4, to support diagnosis and monitoring of thyroid health.
Free Thyroxine Index
The Free Thyroxine Index (FTI) is a calculated value used to assess thyroid hormone activity in the body. It estimates the amount of biologically active thyroxine (T4) by accounting for variations in thyroid hormone–binding proteins, providing a more accurate reflection of thyroid function than total T4 alone.
This test is commonly used to help evaluate thyroid disorders such as hypothyroidism or hyperthyroidism. It is often ordered alongside other thyroid tests, including TSH and total T4, to support diagnosis and monitoring of thyroid health.
