Primary hyperparathyroidism

Alternative names:

parathyroid related hypercalcemia

Definition:

Increased activity of the parathyroid gland with excessive production of parathyroid hormone, caused by enlargement of one or more of the glands.

Causes, incidence, and risk factors:

The parathyroid glands are located at the front and base of the neck at the 4 corners of the thyroid gland. The glands produce parathyroid hormone, which regulates calcium, phosphorus, and magnesium balance within the blood and normal bone mineralization. In primary hyperparathyroidism, increased secretion of parathyroid hormone occurs because of enlargement of 1 or more of the glands, or because of parathyroid adenoma. The effects of increased calcium are seen in several body systems including the skeletal, gastrointestinal, renal, muscular, and central nervous system.

The disease may occur at any age, but most frequently affects those between 30 and 50 years old. It occurs more often in women than men. The incidence is 6 out of 100,000 people.

In children, hyperparathyroidism tends to be caused by hyperplasia (increased number of cells) of all of the parathyroid glands. Hyperparathyroidism in childhood is usually familial (it occurs in families).