To determine hyperthyroidism through the five thyroid function tests, it depends on how the levels of thyroid hormones in the five thyroid function tests change, such as free thyroid hormone, free triiodothyronine, or total thyroid hormone and total triiodothyronine levels are significantly elevated, while the feedback leads to a decrease in thyrotropin levels. If this hormone level is changed, basically the thyroid function level is considered to be elevated. The other five items of thyroid function are thyroglobulin antibodies and thyroid peroxidase, but elevated levels of these two antibodies are not particularly significant for the diagnosis of hyperthyroidism, but are more significant for the diagnosis of Hashimoto’s thyroiditis. The most critical antibody is the thyroid receptor antibody. If the level of thyroid receptor antibody is also significantly increased, the diagnosis of primary hyperthyroidism can be made.