Also known as: Total T3; Free T3; FT3
Formal name: Triiodothyronine
Why should I do it?
To help diagnose hyperthyroidism
When should I do it?
When a person has an abnormal TSH or T4 result or has symptoms of hyperthyroidism
What Kind of Sample is Needed?
A blood sample taken from a vein in the arm
Test Preparation Needed?
None needed; however, certain medications can interfere with the T3 test, so tell your doctor about any drugs that you are taking.