Thyroid

Key facts A thyroid function test is the combination of thyroid stimulating hormone (TSH), thyroxine (T4), and triiodothyronine (T3) blood tests. Thyroid function tests are used to check for thyroid problems. If you are taking thyroid replacement medicine, thyroid function tests are used to check your dose is right. What are thyroid function tests? Thyroid function tests are used to check for thyroid problems. The tests measure the amount of thyroid stimulating hormone (TSH), thyroxine (T4), and triiodothyronine (T3) in your blood. The pituitary gland in your brain makes TSH and sends it to your thyroid gland. TSH controls the