A free or total triiodothyronine (free T3 or total T3) test is used to assess thyroid function. It is ordered primarily to help diagnose hyperthyroidism and may be ordered to help monitor treatment of a person with a known thyroid disorder.T3 and T4 (thyroxine) are hormones produced by the thyroid gland. They help control the rate at which the body uses energy and are regulated by a feedback system. Thyroid-stimulating hormone (TSH) stimulates the production and release of T4 (primarily) and T3. As needed, T4 is converted into T3 by the liver and other tissues.Most of the T4 and T3 circulates in the blood bound to protein, while a small percentage is free (not bound). Blood tests can measure total T4 (unbound plus bound), free T4, total T3 (bound plus unbound), or free T3.Since most T3 is bound to protein, the total T3 can be affected by protein levels and protein binding ability, but the free T3 is not. However, some professional guidelines recommend the total T3, so either test may be used to assess thyroid function. For example, free T3 or sometimes total T3 may be ordered along with thyroid antibodies to help diagnose Graves disease, an autoimmune disorder that is the most common cause of hyperthyroidism.</p>
Sample Type - Blood
Reporting Time - Please Call Customer care
Prerequisites - No special preparation required
Price - ₹130/-
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