T4 (Thyroxine) Test

The T4 test measures the level of thyroxine, a key hormone produced by the thyroid gland. Thyroxine regulates metabolism, growth, and energy production in the body. This test helps evaluate thyroid function and can detect conditions such as hypothyroidism (low thyroid activity) or hyperthyroidism (overactive thyroid). Sample required: Blood Types of T4 tests: Total T4: Measures all thyroxine in the blood (bound + free) Free T4: Measures the unbound, active form of thyroxine Purpose: Assess thyroid function Monitor thyroid treatment Investigate unexplained weight changes, fatigue, or other thyroid-related symptoms