Triiodothyronine T3 is elevated, which requires perfect thyroid function, thyroid ultrasound, thyroid ECT and other tests. If it is primary hyperthyroidism, it needs to be treated by drugs, iodine-131, surgery, etc. If it is central hyperthyroidism, it usually needs surgery. If only T3 is high and the rest of the test results are normal, regular review is sufficient. 1. T3 is elevated, T4 is elevated, and TSH level is lowered. This is usually primary hyperthyroidism, which is the overproduction of thyroid hormone caused by the disease of the thyroid gland itself. Examples include Graves’ disease and autonomous high-functioning adenoma of the thyroid gland, of which Graves’ disease is the most common, and treatments include antithyroid medication, iodine-131 therapy, and surgery. In the case of high-functioning thyroid adenoma, surgery is the treatment of choice. 2. Elevated T3, T4 and TSH levels, which are usually characterized by central hyperthyroidism, i.e., hypothalamic-pituitary lesions leading to overproduction of thyroid hormones. For example, pituitary TSH tumors can lead to central hyperthyroidism, and the treatment is mainly surgical. 3. If only T3 is elevated and other indicators of thyroid hormones are normal, no special treatment is needed, only regular review is required. In conclusion, if T3 is high, you need to consult the doctor in time and have appropriate treatment under the doctor’s guidance.