Hyperparathyroidism (HPT) is a condition caused by the overactivity of the parathyroid glands, the four small glands that surround the thyroid. Located in the neck, the parathyroid glands produce parathyroid hormone, or PTH, a hormone responsible for balancing the calcium and phosphorous in the body. When the body’s blood calcium levels fall, the parathyroid glands release PTH to help restore the depleted levels. Patients with hyperparathyroidism have exceedingly high levels of blood calcium, which can often cause problems like kidney stones, benign tumors known as adenoma, and even osteoporosis.