Triiodothyronine, also known as T3, is a thyroid hormone. It affects almost every physiological process in the body, including growth and development, metabolism, body temperature, and heart rate.

The determination of tri iodo thyronine is one of the sensitive indexes in the diagnosis of hyperthyroidism.

When elevating hyperthyroidism, it is also the precursor of the recurrence of hyperthyroidism. In addition, pregnancy and acute hepatitis will advance Hypothyroidism, simple goiter, acute and chronic nephritis, chronic hepatitis, cirrhosis of the liver.