Thyroid antibody test, thyroglobulin antibody test
This blood test looks for antibodies made by your body in response to thyroglobulin, a protein made by the thyroid gland. The thyroid is a small, butterfly-shaped gland in the lower-front of your neck that makes the hormones T3 and T4. These hormones help control your metabolism, the process in which your body uses energy.
The thyroglobulin antibody test can help diagnose thyroid problems. These include Hashimoto's thyroiditis and autoimmune thyroid disease.
You may need this test if your healthcare provider suspects that you have a thyroid disorder. Thyroglobulin antibodies may be found in people who have a thyroid problem, such as underactive thyroid (hypothyroidism) or overactive thyroid (hyperthyroidism). Thyroglobulin antibodies attack thyroglobulin proteins and can destroy the thyroid gland itself.
You may have this test to confirm the results of another thyroid test—the thyroglobulin test. This test measures levels of the thyroglobulin protein.
If you've been treated for thyroid cancer, this test could be part of regular checkups to monitor your condition.
Symptoms of thyroid problems depend on whether you have an overactive or underactive thyroid.
Overactive thyroid symptoms include:
Feeling weak and fatigued
Trembling of hands and fingers
Feeling anxious, nervous, or irritable
Rapid or irregular heartbeat
Low tolerance for heat
Underactive thyroid symptoms include:
Digestive problems, including constipation
Problems with menstruation
Tiredness and a lack of energy
Hair and skin dryness
A frequent feeling of being cold
Your healthcare provider may test your blood sample to measure levels of other hormones involved in thyroid functions. These are:
TSH, or thyroid-stimulating hormone, made in the pituitary gland
T4 hormone, or thyroxine
T3 hormone, or triiodothyronine
You may also have a thyroglobulin test.
Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your healthcare provider.
Normal test results are negative. This means you have no thyroglobulin antibodies in your blood. A positive test means that you have thyroglobulin antibodies in your blood. This may mean you have a problem with your thyroid gland. A positive thyroglobulin antibody test result may also mean that your thyroglobulin test measurement is incorrect.
The test requires a blood sample, which is drawn through a needle from a vein in your arm.
Taking a blood sample with a needle carries risks that include bleeding, infection, bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight stinging sensation or pain. Afterward, the site may be slightly sore.
Taking thyroid hormone medicines can affect your test results.
Talk with your healthcare provider beforehand about skipping any medicines you are taking on the day of your test. You may also be asked to fast starting the night before the test.
In addition, be sure your provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.