Hyperparathyroidism is caused by the excessive production of parathyroid hormone by one or more of the parathyroid glands. This over activity of the parathyroid glands results in the excess production of parathyroid hormone (PTH).
Primary hyperparathyroidism is most commonly caused by one or more of the parathyroid glands forming a tumor that secretes excessive parathyroid hormone. This enlarged parathyroid gland tumor is called a parathyroid adenoma. Primary hyperparathyroidism is rarely caused by parathyroid cancer. The abnormal parathyroid adenoma does not stop secreting PTH in response to a normal or elevated calcium level in the blood stream. This causes an elevated calcium level in the blood.Symptoms of primary hyperparathyroidism include bone pain, osteoporosis (thin bones), kidney stones, and abdominal discomfort. Primary hyperparathyroidism is usually suspected from elevated calcium level in the blood stream. Usually an elevated calcium level, kidney stones or osteoporosis leads to a further workup to rule out hyperparathyroidism.In almost all cases, the recommendation is for surgery to remove the abnormal parathyroid adenoma. No other medication or treatment can cure primary hyperparathyroidism.
Secondary hyperparathyroidism is caused by medical conditions that cause low blood calcium levels. In response to this low calcium level, the parathyroid glands react and produce PTH. The PTH is elevated beyond the normal limits because the body is trying to increase the calcium levels in the blood stream. Conditions that cause secondary hyperparathyroidism include vitamin D deficiency, kidney disease and calcium deficiency. Treatment for secondary hyperparathyroidism is focused on correcting the underlying cause of the low calcium levels. This usually includes vitamin D and calcium supplements. Surgery is sometimes indicated, but not as often as with primary hyperparathyroidism, where surgery is nearly always recommended.