Thyroid antibody tests measure the levels of antibodies that can destroy thyroid tissue or make the cells produce thyroid hormones. They are blood tests.
The body’s immune system makes antibodies to fight infections. But sometime those antibodies attack the body’s tissues instead. This is called an autoimmune reaction.
People who have one autoimmune disease may get another one. Tell your doctor if you have any new or worse symptoms.
These tests are not thyroid hormone tests. High or low levels of thyroid hormones also can be signs of thyroid problems. These antibody tests may be done after thyroid hormone tests to find the cause of high or low levels of thyroid hormones.
High levels of these antibodies usually suggest that a person has an autoimmune thyroid problem. But some people who have thyroid problems don’t test positive for these antibodies. And some people who have these antibodies don’t get thyroid disease.