immune system may produce antithyroid
antibodies. These antibodies destroy thyroid tissue. This test can find out if you have these antibodies.
High levels of antithyroid antibodies may mean that you have autoimmune hypothyroidism (Hashimoto's thyroiditis). Or you may have autoimmune hyperthyroidism (Graves' disease). But some people who have
hypothyroidism or hyperthyroidism never test positive for these antibodies. And some people who
test positive may never get hypothyroidism or hyperthyroidism.
If you have mild (subclinical) hypothyroidism, you may get this test. It
can help predict how likely it is that you will get
hypothyroidism that will later cause symptoms.