Thyroid Function Tests
The thyroid gland is a small, butterfly-shaped gland located in the front of your neck. It produces thyroid hormones, which are essential for many bodily functions, including metabolism, growth, and development.
Thyroid function tests are used to measure the amount of thyroid hormones in your blood. These tests can help your doctor diagnose and manage thyroid problems, such as hypothyroidism (an underactive thyroid) and hyperthyroidism (an overactive thyroid).
Types of Thyroid Function Tests
There are several different types of thyroid function tests. The most common tests include:
- Thyroid-stimulating hormone (TSH) test: This test measures the amount of TSH in your blood. TSH is a hormone produced by the pituitary gland, which is located at the base of your brain. TSH tells your thyroid gland to produce thyroid hormones.
- Free T4 (FT4) test: This test measures the amount of free T4 in your blood. Free T4 is the form of T4 that is not bound to proteins in your blood.
- Free T3 (FT3) test: This test measures the amount of free T3 in your blood. Free T3 is the active form of T4.
- Thyroid antibodies test: This test measures the amount of antibodies to thyroid peroxidase (TPO) and thyroglobulin (Tg) in your blood. TPO and Tg are proteins that are involved in the production of thyroid hormones.
Why Are Thyroid Function Tests Done?
Thyroid function tests may be ordered for a variety of reasons, including:
- To screen for thyroid problems
- To diagnose thyroid problems
- To monitor the treatment of thyroid problems
- To assess the risk of developing thyroid problems
What to Expect Before and After a Thyroid Function Test
There is no special preparation needed for a thyroid function test. You may be asked to fast for several hours before the test.
A thyroid function test is a simple blood test that is usually performed in a doctor’s office or laboratory. A small amount of blood will be drawn from a vein in your arm. The test usually takes only a few minutes.
There are no known risks associated with thyroid function tests.
What Are the Results of a Thyroid Function Test?
The results of a thyroid function test will be interpreted by your doctor. The normal ranges for thyroid function tests vary depending on your age, sex, and other factors.
If your thyroid function test results are abnormal, your doctor may order additional tests to determine the cause of the problem. Treatment for thyroid problems will vary depending on the underlying cause.
Thyroid Function Tests and Your Health
Thyroid function tests are an important tool for diagnosing and managing thyroid problems. If you have any concerns about your thyroid health, talk to your doctor.