The parathyroid glands are four pea-size glands that regulate the level of calcium in the bloodstream. Typically located behind the thyroid gland, they can be found anywhere from below the jaw to the chest area.
Parathyroid disease occurs when the parathyroid glands create an excessive amount of parathyroid hormone, a condition also known as hyperparathyroidism. The secretion of excess hormone removes needed calcium from the bones, leading most noticeably to osteoporosis. Hyperparathyroidism can also cause damage to the nervous system, which relies on calcium, and the kidneys, which are critical to conserving calcium.
Hyperparathyroidism occurs when a tumor develops in one of the parathyroid glands. Nearly 99 percent of these tumors, which occur in only one out of every 50,000 people, are benign. More women than men are diagnosed with the disease, which occurs commonly between the ages of 30 and 55.
There are two types of hyperparathyroidism – Parathyroid Adenoma and Parathyroid Hyperplasia.
A parathyroid adenoma is the enlargement of a parathyroid gland. This is referred to as primary hyperparathyroidism. Approximately 93 percent of all hyperparathyroidism patients are diagnosed with a single adenoma. The tumor in the diseased gland secretes extra hormone, causing the healthy glands to react by becoming dormant. This inactivity causes the healthy glands to eventually shrink (sometimes to the size of a grain of rice) while the diseased gland grows larger.
Patients suffering from multiple adenomas have two enlarged glands and two healthy glands. This occurs in only 1 percent to 2 percent of patients.
Approximately five to six percent of all hyperparathyroid patients are diagnosed with hyperplasia, the enlargement of all four parathyroid glands, which is also referred to as primary hyperparathyroidism. These presentations can be familial or sporadic.
Patients with hyperplasia that also have a serious, chronic kidney insufficiency are said to have secondary hyperparathyroidism.