Thyroxine (T4) Test

The Thyroxine (T4) test measures the level of T4 hormone in your blood, which is one of the main hormones produced by the thyroid gland. T4 plays a vital role in regulating metabolism, energy levels, and overall hormonal balance.

This test helps assess how well the thyroid is functioning and is commonly used to investigate symptoms of thyroid disorders, including hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid). Depending on the clinical need, the test may measure either total T4 or free T4—the portion of the hormone available for the body to use.