What is Triiodothyronine (T3)?
Triiodothyronine is measured as part of a thyroid panel. Your T3 (active thyroid hormone) is in the normal range.
What does a high Triiodothyronine mean?
Elevated T3 suggests hyperthyroidism — your thyroid is producing too much active hormone.
What does a low Triiodothyronine mean?
Low T3 can indicate hypothyroidism or a low-T3 syndrome seen in chronic illness. Often evaluated together with TSH and T4.
Understand your whole report, not just one number
A single value rarely tells the full story — Triiodothyronine is best read alongside the rest of your panel. Paste your values or upload your report and get a plain-English explanation of every marker, with the important results flagged.