Definition of Hypoparathyroidism:

Hypoparathyroidism is is an endocrine disorder in which the parathyroid glands in the neck do not produce enough parathyroid hormone (PTH).

See also: Hyperparathyroidism

Causes, incidence, and risk factors:

The parathyroid glands help control calcium use and removal by the body. They do this by producing parathyroid hormone, or PTH. PTH helps control calcium, phosphorus, and vitamin D levels within the blood and bone.

Hypoparathyroidism occurs when the glands produce too little PTH. Blood calcium levels fall, and phosphorus levels rise.

The most common cause of hypoparathyroidism is injury to the parathyroid glands during head and neck surgery. Rarely, hypoparathyroidism is a side effect of radioactive iodine treatment for hyperthyroidism.

Hypoparathyroidism may also be caused by

• Low blood magnesium levels
• Metabolic alkalosis

DiGeorge syndrome is a childhood disease in which hypoparathyroidism occurs because all the parathyroid glands are missing at birth. Familial hypoparathyroidism occurs with other endocrine diseases, such as adrenal insufficiency, in a syndrome called type I polyglandular autoimmune syndrome (PGA I).

The risk factors for hypoparathyroidism include recent thyroid or neck surgery, a family history of parathyroid disorder, or certain autoimmune diseases such as Addison's disease.