A total T3 test is usually ordered to evaluate thyroid gland function, diagnose hyperthyroidism or hypothyroidism, and to monitor treatment for these conditions.
When this Serum Total T3 test is required
A total T3 test is usually requested as part of a series of thyroid function tests, which include a TSH (thyroid-stimulating hormone) test and a total T4 test, to assess overall thyroid gland function.
What the Serum Total T3 Test Detects
The total T3 test measures the levels of the thyroid hormone triiodothyronine (T3) in the bloodstream. T3 is one of the two primary thyroid hormones produced by the thyroid gland that regulates the body’s metabolism.
Preparation for the Serum Total T3 Test
Test preparation may vary depending on the healthcare provider, but generally, there is no special preparation needed for this test.
Sample Requirements
A blood sample is required for this test.
Additional Notes
The total T3 test is less commonly used than the free T3 test, which measures the levels of unbound (free) T3 in the bloodstream, as this is thought to better reflect thyroid function.
