Understand Your Test

Free T3 and Total T3

Formal Name

 Free Triiodothyronine; Total Triiodothyronine

Why Get Tested?

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 To Get Tested?

When you have an abnormal TSH, particularly with a normal free T4 result, and/or signs and symptoms of hyperthyroidism.