Definition of Primary hyperparathyroidism:

Primary hyperparathyroidism is an endocrine disorder in which the body has too much parathyroid hormone (PTH).

Causes, incidence, and risk factors:

The parathyroid glands are located at the front and base of the neck at the four corners of the thyroid gland. The glands produce parathyroid hormone, which controls the amount of calcium and phosphorus in the body.

In primary hyperparathyroidism, enlargement of one or more of the parathyroid glands causes extra parathyroid hormone to be released. This increases calcium levels. The effects of increased calcium are seen in several body systems including the skeletal, gastrointestinal, renal (kidney), muscular, and central nervous system.

The disease is most common in people over 60, but can also be seen in younger adults. Women are more likely to be affected than men. Radiation to the head and neck increases risk. Hyperparathyroidism in childhood is very unusual.

Rarely, the disease is caused by parathyroid cancer.