Hyperparathyroidism is the overproduction by the parathyroid glands of a hormone called parathyroid hormone (parathormone). Parathyroid glands are four pea-sized glands located just behind the thyroid gland in the front of the neck. Parathyroid hormone (parathormone) helps regulate the levels of calcium and phosphorus in the body.
Thyroid glands and parathyroid glands, despite their similar names and proximity, are entirely separate, and each produces hormones with different functions.
Hyperparathyroidism may be primary or secondary. It most often occurs in patients over age 30, and most commonly in patients 50 to 60 years old. It rarely occurs in children or the elderly. Women are affected by the disease
up to three times more often than men. It is estimated that 28 of every 100,000 people in the United States will develop hyperparathyroidism each year.
Normally, parathyroid glands produce the parathormone as calcium levels drop and lower to meet the demands of a growing skeleton, pregnancy, or lactation. However, when one or more parathyroid glands malfunction, it can lead to overproduction of the hormone and elevated calcium level in the blood. Therefore, a common result of hyperparathyroidism is hypercalcemia, or an abnormally high level of calcium in the blood.
Primary hyperparathyroidism occurs as a malfunction of one of the glands, usually as a result of a benign tumor called an adenoma. Secondary hyperparathyroidism occurs as the result of an abnormality outside the parathyroid glands related to the body's metabolism, or chemical changes in living cells that help provide the body's energy. These changes cause a resistance to the function of the parathyroid hormones. Primary hyperparathyroidism is one of the most common endocrine disorders, led only by diabetes and hyperthyroidism.
Mai Tran, Teresa G. Odle, The Gale Group Inc., Gale, Detroit,