Thyroid
Also known as: Thyroxine, Total T4 concentration, Free T4 Index (FTI)
If you experience severe symptoms like a very rapid or irregular heartbeat, significant unexplained weight loss, extreme fatigue, or sudden changes in mood, contact your clinician or seek urgent care.
This test checks the total amount of thyroxine in your blood. Thyroxine is a hormone your thyroid gland makes. It measures both the active hormone and the part that is connected to proteins.
Doctors often order this test to see how well your thyroid gland is working. They might order it if you have signs of a thyroid that is too active or not active enough. This test can also help check on other thyroid test results.
Reference ranges for T4 can vary by laboratory, and interpretation may depend on age, sex, pregnancy status, and other clinical factors.
Clinical Reference
1730608195082306Medicare covers for vitamin D deficiency evaluation; ABN may be required for screening
Educational purposes only — This information is not a substitute for professional medical advice, diagnosis, or treatment. Always discuss your lab results with your healthcare provider.