Hypoparathyroidism is a disorder in which the parathyroid glands in the neck do not produce enough parathyroid hormone (PTH).
There are four tiny parathyroid glands in the neck, near or attached to the back side of the thyroid gland.
The parathyroid glands help control calcium use and removal by the body. They do this by producing parathyroid hormone (PTH). PTH helps control calcium, phosphorus, and vitamin D levels in the blood and bone.
Hypoparathyroidism occurs when the glands produce too little PTH. The blood calcium level falls, and the phosphorus level rises.
The most common cause of hypoparathyroidism is injury to the parathyroid glands during thyroid or neck surgery. It may also be caused by any of the following:
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 reduce symptoms and restore the calcium and mineral balance in the body.
Treatment involves calcium carbonate and vitamin D supplements. These 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. But changes in the teeth, cataracts, and brain calcifications cannot be reversed in children who have undiagnosed hypoparathyroidism during development.
Hypoparathyroidism in children may lead to poor growth, abnormal teeth, and slow mental development.
Too much treatment with vitamin D and calcium can cause high blood calcium (hypercalcemia) or high urine calcium (hypercalciuria). Excess treatment may sometimes interfere with kidney function, or even cause kidney failure.
Bringhurst FR, DeMay MB, Kronenberg HM. Hormones and disorders of mineral metabolism. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 28.
Doyle DA. Hypoparathyroidism. In: Kliegman RM, Stanton BF, St. Geme JW III, et al., eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 565.
Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.