Total Triiodothyronine (Total T3)
Here’s what it reflects — and what to do about it.
Longetic pulls together every lab and record you’ve had, follows how Total Triiodothyronine (Total T3) changes over time, and explains what’s shifting — so you walk into your next appointment prepared, with reminders for retests along the way.
What is Total Triiodothyronine (Total T3)?
Measures all of the active thyroid hormone triiodothyronine in your blood, both the free portion and the part bound to proteins.
Triiodothyronine, or T3, is one of the main thyroid hormones that set the pace of your metabolism, and the total T3 test measures the free and protein-bound amounts together. Higher levels can be associated with an overactive thyroid, while lower levels can be associated with an underactive thyroid or with non-thyroid illness. T3 is usually checked as part of a broader thyroid panel with TSH and T4 rather than on its own.
What to know about Total Triiodothyronine (Total T3)
Understanding Total Triiodothyronine (Total T3) means knowing what it reflects, what tends to move it, and the signs that suggest it’s worth a closer look — so you can bring the right questions to your next appointment.
This glossary entry is for informational purposes only and is not a substitute for professional medical advice. Read our Medical Disclaimer.
References
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