Thyroglobulin antibodies are autoantibodies to the thyroid gland that bind to thyroid tissue and destroy it, causing a variety of thyroid disorders. The antibody is mainly found in patients with autoimmune thyroid disease and non-thyroidal autoimmune diseases, but can also be detected in a few healthy individuals, especially in the elderly. The normal reference range for antithyroglobulin antibodies generally varies depending on the hospital, the test method and the instrumentation used. If the ECLIA method is used, the result is often less than 115 IU/mL. Therefore, if the test value reaches 300 IU/mL, it indicates Hashimoto’s thyroiditis or hyperthyroidism. In addition, thyroid malignancies such as follicular carcinoma, papillary thyroid carcinoma or interstitial carcinoma may also show varying degrees of elevated thyroglobulin antibodies. Therefore, if thyroglobulin antibodies reach 300 IU/mL, further clinical manifestations, laboratory tests, thyroid ultrasound and MRI should be combined to clarify the cause. If the thyroglobulin antibody index is abnormal, but the thyroid function TSH, FT3 and FT4 are normal, no medication is needed, just pay attention to the observation and review the thyroid function regularly.