Hyperparathyroidism

Hyperparathyroidism is an excess of parathyroid hormone in the bloodstream due to overactivity of one or more of the body's four parathyroid glands. These oval, grain-of-rice-sized glands are located in your neck. The parathyroid glands produce parathyroid hormone, which helps maintain an appropriate balance of calcium in the bloodstream and in tissues that depend on calcium for proper functioning.