Hyperparathyroidism

Chest | Endocrinology and Metabolism | Hyperparathyroidism (Disease)


Description

If the parathyroid glands secrete too much hormone, as happens in primary hyperparathyroidism, the balance is disrupted: Blood calcium rises. This condition of excessive calcium in the blood, called hypercalcemia, is what usually signals the doctor that something may be wrong with the parathyroid glands.

There are two main types of hyperparathyroidism. Primary hyperparathyroidism is caused by enlargement of one or more of the parathyroid glands. This leads to too much parathyroid hormone, which raises the level of calcium in the blood. The term hyperparathyroidism generally refers to primary hyperparathyroidism.

Secondary hyperparathyroidism is when the body produces extra parathyroid hormone because the calcium levels are too low. This is seen when vitamin D levels are low or when calcium is not absorbed from the intestines. Correcting the calcium level and the underlying problem will bring the parathyroid levels in the normal range.

If the parathyroid glands continue to produce too much parathyroid hormone even though the calcium level is back to normal, the condition is called tertiary hyperthyroidism. It occurs especially in patients with kidney problems.

Causes and Risk factors

In 85 percent of people with primary hyperparathyroidism, a benign tumor called an adenoma has formed on one of the parathyroid glands, causing it to become overactive. Benign tumors are noncancerous.

In most other cases, the excess hormone comes from two or more enlarged parathyroid glands, a condition called hyperplasia. Very rarely, hyperparathyroidism is caused by cancer of a parathyroid gland.

This excess PTH triggers the release of too much calcium into the bloodstream. The bones may lose calcium, and too much calcium may be absorbed from food. The levels of calcium may increase in the urine, causing kidney stones. PTH also lowers blood phosphorus levels by increasing excretion of phosphorus in the urine.

When calcium levels are too low, the body responds by increasing production of parathyroid hormone. This increase in parathyroid hormone causes more calcium to be taken from the bone and more calcium to be reabsorbed by the intestines and kidney. When the calcium level returns to normal, parathyroid hormone production slows down.

Diagnosis and Treatment

Treatment depends upon the severity and cause of the condition. If you have mildly increased calcium levels due to primary hyperparathyroidism and no symptoms, you may just need regular checkups with your doctor.

If symptoms are present or calcium level is very high, surgery may be needed to remove the parathyroid gland that is overproducing the hormone. ...