Thyroid Antibodies

Thyroid Antibodies

Thyroid antibodies are proteins produced by the immune system to attack thyroid cells. They are commonly found in those with autoimmune thyroid conditions, such as Hashimoto’s thyroiditis and Grave’s disease. Thyroid antibodies also play a role in postpartum thyroiditis and other thyroid-related conditions.


No advance preparation is necessary for a thyroid antibody test. You do not need to fast before the test, and can take your medications as prescribed.


The procedure for a thyroid antibody test involves a simple blood draw. You will be asked to sit or lie down while a health care professional draws a sample of your blood, usually from your arm.


There are two main types of thyroid antibodies that are tested for: Thyroid Peroxidase Antibodies (TPO) and Thyroglobulin Antibodies (TgAb). TPO antibodies are the most common type and are typically used as a screening test for Hashimoto's thyroiditis and other autoimmune conditions. TgAb antibodies are another useful marker for autoimmune thyroiditis, but are often not included in the initial thyroid antibody tests.

Why Test?

Thyroid antibody tests are used to help diagnose thyroid conditions that are linked to autoimmune-related causes. They can also be used to monitor treatment and to detect relapse. In pregnant women, thyroid antibody tests may be recommended to diagnose postpartum thyroiditis.

When to Test

Thyroid antibody tests are usually ordered when a person is experiencing symptoms of an autoimmune thyroid condition, or when the doctor suspects the person may have a condition related to autoimmune triggers. Pregnant women may have a thyroid antibody test to detect postpartum thyroiditis. Thyroid antibody tests can also be ordered for follow-up and monitoring of treatment.


The risks associated with a thyroid antibody test are minimal. The test involves a simple blood draw, and the risks associated with that procedure are also minimal. The most common risks are bruising, pain, and bleeding.