Triiodothyronine (T3), Free CPT: 84481
Expected Turnaround Time
Within 1 – 2 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
0.3 mL (Note: This volume does not allow for repeat testing.)
Red-top tube or gel-barrier tube
If a red-top tube is used, transfer separated serum to a plastic transport tube.
Maintain specimen at room temperature.
To help evaluate thyroid gland function; to diagnose thyroid disease, including hyperthyroidism, and determine the cause; to monitor effectiveness of treatment of a thyroid disorder.
When you have an abnormal thyroid stimulating hormone (TSH), particularly with a normal free thyroxine (T4) result, and/or signs and symptoms of hyperthyroidism.
A blood sample drawn from a vein in your arm.
None needed; however, certain medications, multivitamins and supplements can interfere with the free T3 and total T3 tests, so tell your healthcare practitioner about any prescribed or over-the-counter drugs and/or supplements that you are taking. Acute illness may affect thyroid testing test results. It is generally recommended that thyroid testing be avoided in hospitalized patients or deferred until after a person has recovered from an acute illness.