High parathyroid hormone is not hyperthyroidism. Parathyroid hormone is a hormone secreted by the parathyroid glands. Parathyroid hormone promotes calcium absorption and deposits in bones, and is an important hormone that affects calcium and phosphorus metabolism. When parathyroid hormone is secreted in excess due to parathyroid adenoma or parathyroid hyperplasia, the body will develop hypercalcemia and produce corresponding multisystem symptoms. When hypoparathyroidism leads to decreased secretion of parathyroid hormone, hypoparathyroidism occurs, resulting in hypocalcemia, convulsions, and other symptoms. Hyperthyroidism, on the other hand, is a hypermetabolic syndrome caused by high concentrations of thyroid hormones in the blood due to various reasons, and in most cases is the result of hyperthyroidism. The thyroid and parathyroid glands are located directly in front of the neck, but the parathyroid and thyroid glands are two completely different glands that secrete different hormones and perform different regulatory functions on the body.