What Are Thyroid Autoantibodies?

The thyroid gland is in the front of the neck. It makes hormone that controls metabolism. Thyroid autoantibodies are made by the body's own immune system. They see the gland as foreign object and attack it. This can cause destroy the gland or cause it to make too much thyroid hormone.

Reason for the Test

Thyroid autoantibody tests are done to diagnose and monitor autoimmune thyroid diseases.

Type of Sample Taken

A blood sample will be taken from a vein in the arm.

During the Sample Collection

You will be asked to sit. An area inside your elbow will be cleaned with a wipe. A large band will be tied around your arm. The needle will be put in a vein. A tube will collect the blood from the needle. The band on your arm will be taken off. After the blood is collected, the needle will be removed. Gauze will be held on the site to help stop bleeding. You may also be given a bandage. This test takes about 5 to 10 minutes.

After Collecting the Sample

After the blood sample is taken, you may need to stay seated for 10 to 15 minutes. If you are lightheaded, you may need to stay seated longer. When you feel better, you can leave.

A bit of blood may ooze from the vein beneath the skin. It will cause a bruise. A bruise will usually fade in a day or two.

Call your doctor right away if you have redness, swelling, lasting bleeding, or pain.

Results

You should get your results in a few days.

Depending on the exact thyroid autoantibody measured, high levels of thyroid autoantibodies can points to problems like:

• Hypothyroidism—when the gland does not make enough hormone
• Hyperthyroidism—when the gland makes too much hormone
• Other problems with the immune system, such as celiac disease, rheumatoid arthritis, systemic lupus erythematosus, and myasthenia gravis

Talk to your doctor about your test results. A test may point to an illness that you do not have. It can also miss an illness that you may have. The doctor will check your symptoms and all test results before making a diagnosis.