What is normal free thyroxine index?

What is normal free thyroxine index?

In an adult, the typical range for free T4 is between . 8 and 1.8 nanograms per deciliter. 10 An abnormally high free T4 level may indicate hyperthyroidism, thyroiditis, or goiter. It may also lead to additional tests for Graves’ disease.

What does high free thyroxine index mean?

High levels of any of these tests (total T4, free T4, or free T4 index) may indicate an overactive thyroid, also known as hyperthyroidism. Low levels of any of these tests (total T4, free T4, or free T4 index) may indicate an underactive thyroid, also known as hypothyroidism.

Is free thyroxine index the same as TSH?

Tests measuring free T4 – either a free T4 (FT4) or free T4 index (FTI) – more accurately reflect how the thyroid gland is functioning when checked with a TSH. The finding of an elevated TSH and low FT4 or FTI indicates primary hypothyroidism due to disease in the thyroid gland.

What is the normal free T4 thyroid range?

Free T4, which tests for the amount of T4 that is available in the body, should range between 0.8 to 1.8 nanograms per deciliter (ng/dL).

What happens if thyroxine is high?

Hyperthyroidism (overactive thyroid) occurs when your thyroid gland produces too much of the hormone thyroxine. Hyperthyroidism can accelerate your body’s metabolism, causing unintentional weight loss and a rapid or irregular heartbeat. Several treatments are available for hyperthyroidism.

When do you use the free thyroxine index?

The free thyroxine index has generally been replaced by Free Thyroxine in the assessment of thyroid function, but is occasionally useful when a free T4 result is suspected of being anomalous. How to calculate the free thyroxine index?

Which is better free T4 or total thyroxine?

In most cases, free thyroxine (also known as free T4) is good indicator of thyroid function, along with TSH and other measures. Free thyroxine is often more useful than total thyroxine in assessing thyroid function.

Is the FTI the same as serum thyroxine?

The FTI is a normalized determination that is known to be relatively constant in healthy individuals and to compensate for abnormal levels of binding proteins. Currently, direct measurement of serum free thyroxine is starting to replace the FTI formula in most clinical situations.

What does it mean if your free thyroxine result is too high?

What does it mean if your Free Thyroxine result is too high? Elevated free thyroxine levels may indicate hyperthyroidism, thyroid hormone resistance syndrome, or thyroxine toxicosis.