What is thyroid 4 test?
There are two types of tests for T4.Total T4Free T4Total testing is antiquated and no longer useful since the Free T4 test was devised. Total testing tells you how much total amount of T4 is in your blood. This includes the T4 that is bound to other proteins and hormones that cannot be used by the body, so is an inaccurate test.Free testing is the current gold standard, most accurate way to test T4. It shows how much of the T4 is floating freely, ready to be used by the body by conversion to T3.