Thyroid Test (TSH, T-4, FREE)

This is a test that measures the amount of the hormone TSH in the blood and is used as a screening test for abnormal thyroid. TSH, a hormone produced in the pituitary gland, stimulates the thyroid gland to release TSH to the rest of the body.

In addition, since thyroid disorders usually appear when there is a net change of free unbound fractions over a period of time, the best measure of thyroid status is the concentration of free hormones. Serum level of free T4 (FT4), included in this test, correlates very well with secretion and metabolism rate of T4.

Special Preparation: None.

More Detailed TSH Test Information

More Detailed T4 Test Information