Antithyroglobulin antibody of more than 1000 suggests that there may be thyroid diseases, such as Hashimoto’s thyroiditis, hyperthyroidism, thyroid cancer, etc. Some of the diseases are more serious, and it is recommended to complete the relevant examinations to assess the severity. Thyroglobulin is a glycoprotein synthesized by thyroid follicular cells, and anti-thyroglobulin is mainly IgG, which is usually negative in normal people. Thyroglobulin antibodies of 1000 are usually abnormally elevated and may be seen in certain disease states, such as Hashimoto’s thyroiditis, hyperthyroidism, and thyroid cancer, in which patients may be positive for anti-thyroglobulin antibodies. The severity depends on the cause of the elevation. It is recommended to seek prompt medical attention when elevated levels are detected, and to have the cause of the elevation clarified by a medical professional in conjunction with other ancillary tests, such as thyroid function and thyroid ultrasound, in order to avoid delays in the condition.