A T3 Blood Test measures the amount of triiodothyronine, or T3, in the blood.The thyroid is a butterfly-shaped gland that lies in front of the windpipe (trachea), just below the voice box (larynx). The thyroid gland uses iodine from food to make two important thyroid hormones, thyroxine (T4) and triiodothyronine (T3). The thyroid gland stores these thyroid hormones and releases them, as they are needed.
Measurement of free tri-iodothyronine (T3) is of value in confirming the diagnosis of hyperthyroidism. Take a T3 Total Blood Test at LabSafe for the measurement of free tri-iodothyronine (T3).
Thyroxine (T4) is produced by the thyroid gland when the pituitary gland releases thyroid-stimulating hormone. Almost all of the triiodothyronine is made from thyroxine released by the thyroid gland, with only a small amount produced directly by the thyroid gland itself. Together, T3 and T4 help control the body's metabolism.
T3 has a greater effect on metabolism than T4, even though T3 is normally present in lower amounts than T4. Most T3 is made from T4 by body tissues after T4 is released from the thyroid gland. The rest of the T3 is produced directly by the thyroid gland. The total amount of T3 in the blood or the amount of free T3 (FT3) can be measured. Normally, less than 1% of the T3 is free.
Often a thyroid screening panel with Thyroid Stimulating Hormone (TSH) is performed prior to a Total T3 test.
You may order a T3 Blood Test online, or for more information call LabSafe toll free at 1-888-333-LABS to speak with one of our medical counselors.
