What laboratory test measures thyroid function?

The laboratory test that measures thyroid function is comprised of thyroid function tests. These tests specifically assess the levels of thyroid hormones in the blood, including thyroxine (T4) and triiodothyronine (T3), as well as thyroid-stimulating hormone (TSH). TSH is produced by the pituitary gland and regulates the production of T4 and T3 from the thyroid gland. By measuring these hormones, healthcare providers can evaluate if the thyroid is functioning normally, underactive (hypothyroidism), or overactive (hyperthyroidism).

The other tests mentioned do not evaluate thyroid function and serve different purposes. For instance, a blood glucose test measures the amount of glucose in the blood and is primarily used to diagnose and monitor diabetes. A complete blood count provides information about the different types of cells in the blood, which helps in diagnosing conditions like anemia or infection. Lastly, a lipid profile assesses levels of cholesterol and triglycerides, which is important for evaluating cardiovascular risk but not for assessing thyroid health. Thus, thyroid function tests specifically target the function and health of the thyroid gland.