High thyroid hormones can be caused by Graves’ disease, subacute thyroiditis, excessive iodine intake and other conditions. 1. Graves’ disease: it is an autoimmune thyroid disease, which may cause symptoms such as hyperthyroidism, goiter and proptosis, in which hyperthyroidism will cause elevated thyroid hormones and may be accompanied by decreased thyrotropin. 2. Subacute thyroiditis: Viral infection may cause subacute thyroiditis, which may be characterized by hyperthyroidism in the early stages, followed by elevated thyroid hormones. 3. Excessive iodine intake: If the patient eats iodine-rich food for a long period of time, resulting in excessive iodine intake, it will stimulate the synthesis and secretion of thyroid hormones to increase, resulting in elevated thyroid hormones. It is recommended to go to the hospital to consult a doctor to determine the cause of thyroid hormone elevation and treat the problem.