This test aims to detect antibodies to thyroglobulin, a protein that is exclusive to the thyroid gland. Normally, thyroglobulin remains confined within the thyroid gland and does not enter the bloodstream. However, if the immune system attacks the thyroid gland, as in the case of inflammation, thyroglobulin may be released into the bloodstream and antibodies can be identified. The majority of thyroid disorders result from an autoimmune disorder where the immune system attacks the thyroid gland. In Graves' disease, this causes the gland to produce an excessive amount of thyroid hormone, while in Hashimoto's thyroiditis, the immune system gradually destroys the cells of the thyroid gland, leading to a reduced production of thyroid hormone.