Triiodothyronine, or T3, is an important thyroid hormone that helps maintain muscle control, brain function and development, heart and digestive functions. High or low T3 levels may indicate an ...

A TPO antibody test helps diagnose autoimmune thyroid diseases like Hashimoto’s thyroiditis. A positive test result means antibodies are present and may indicate a thyroid condition, but other tests ...

The thyroid is a small, butterfly-shaped gland located at the front of the neck, but its influence extends across nearly every system in the body. It produces two hormones -- thyroxine (T4) and ...