Thyroxine (T4), Total LabCorp
This test measures the total amount of Thyroxine in the blood to identify whether you have a thyroid disorder.
What is this test?
The Total Thyroxine (T4) Test measures the amount of total T4 in the blood to identify a potential thyroid hormone deficiency. “Total” refers to the amount of bound and unbound T4 in the bloodstream. A Free T4 test is typically considered a more sensitive and accurate diagnostic tool for thyroid disease, but the Total T4 Test can be ordered as an ancillary test to those results.
T4 is a hormone released by the thyroid gland that is responsible for many important functions throughout the body. It is converted into T3, another thyroid hormone, once it reaches the body’s tissues. Symptoms of a T4 deficiency may include: fatigue, anxiety, insomnia, diarrhea, and muscle aches and pains.
Who is this test for?
This test can be ordered for a more in-depth view of total T4 levels in those who are experiencing symptoms of a thyroid disease. We recommend the Complete Thyroid Panel for primary diagnosis of thyroid disease, but the Total T4 Test can provide additional information if necessary.
