Hypoparathyroidism is disorder in which the parathyroid glands in the neck do not produce enough parathyroid hormone (PTH).
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 in 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 thyroid and neck surgery. Rarely, hypoparathyroidism is a side effect of radioactive iodine treatment for hyperthyroidism.
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).
Blood tests will be done to check calcium, phosphorus, magnesium, and PTH levels. An ECG may show abnormal heart rhythms.
A urine test may be done to determine how much calcium is being removed from the body.
The goal of treatment is to restore the calcium and mineral balance in the body.
Treatment involves calcium carbonate and vitamin D supplements, which usually must be taken for life. Blood levels are measured regularly to make sure that the dose is correct. A high-calcium, low-phosphorous diet is recommended.
Persons who have life-threatening attacks of low calcium levels or prolonged muscle contractions are given calcium through a vein (IV). Precautions are taken to prevent seizures or larynx spasms. The heart is monitored for abnormal rhythms until the person is stable. When the life-threatening attack has been controlled, treatment continues with medicine taken by mouth.
The outcome is likely to be good if the diagnosis is made early. However, changes in the teeth, cataracts, and brain calcifications cannot be reversed.
Hypoparathyroidism in children may lead to poor growth, abnormal teeth, and slow mental development.
Too much treatment with vitamin D and calcium can cause hypercalcemia (high blood calcium) and may sometimes interfere with kidney function.
Doyle DA. Hypoparathyroidism. Kliegman RM, Stanton BM, St. Geme J, Schor N, Behrman RE, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 565.
Shehzad Topiwala, MD, Chief Consultant Endocrinologist, Premier Medical Associates, The Villages, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.