Hypoparathyroidism is a disorder that occurs when the parathyroid glands (the four pea-size glands around the thyroid gland at the base of the neck) fail to produce sufficient quantities of parathyroid hormone (PTH), which helps regulate the blood level of calcium by its actions on the bones and the kidneys. Lack of PTH results in reduced levels of calcium in the blood, which can produce a variety of neurological and muscle abnormalities, from paresthesia (numbness or a burning or prickling sensation) to tetany (hyperexcitability of the nerves, characterized by painful spasms, twitching, and cramps in the face, hands, arms, throat, and sometimes the feet). Such symptoms usually subside with treatment, although the disorder tends to develop gradually, so that by the time it is treated, it may have already caused certain irreversible complications such as cataracts or brain calcifications.
When hypoparathyroidism occurs during childhood and is not treated properly, it may result in poor tooth development and, sometimes, mental retardation. Otherwise, when diagnosis is established early in the course of the disorder, prognosis is good.
WHAT CAUSES HYPOPARATHYROIDISM?
- The most common causes of hypoparathyroidism in adults are the accidental removal of parathyroid tissue during thyroid surgery or other neck surgery and the removal or destruction of substantial portions of the parathyroid glands during the treatment of hyperparathyroidism.
- In children, hypoparathyroidism most often results from destruction of the thyroid gland as a result of an autoimmune disorder. This may be associated with type 1 diabetes mellitus and thyroid disorders.
- Hypoparathyroidism may occur when the parathyroid tissue is destroyed by amyloidosis (the buildup of a waxy substance in tissues and organs), hemochromatosis (excess iron storage), or malignant (cancerous) tumors.
- In rare cases, an infant may be born without parathyroid glands or with a congenital malfunction of the glands (DiGeorge’s syndrome).
- Rarely, a child may not be responsive to PTH and may have symptomatic low calcium levels despite an elevated level of PTH (pseudohypoparathyroidism). Frequently, other characteristics such as short stature, obesity, round face, and shortened fourth and fifth fingers may be present.
SYMPTOMS OF HYPOPARATHYROIDISM
- Tingling and numbness or burning and prickling sensations in the face, hands, fingertips, or elsewhere
- Painful, uncontrollable muscle spasms or cramps in the face, hands, and feet (tetany)
- Breathing or swallowing difficulty
- Dry, lusterless skin and hair; split, cracked nails
- Abnormal tooth development in children
- Psychosis (in very severe cases)
- Seizures (in rare cases)
- Difficulty with walking
- Blurred vision due to cataracts
- There is no way to prevent hypoparathyroidism.
- Patient history and physical examination are needed.
- Low blood calcium is suspected when tetany of the hand is produced by inflating a blood pressure cuff on the arm or spasm of the upper lip is elicited by tapping on the cheek.
- Abnormally low blood concentrations of calcium and elevated levels of phosphorus indicate hypoparathyroidism.
- Diagnosis is confirmed by the measurement of low blood levels of PTH.
- To measure calcium, magnesium, phosphorus, vitamin D, and/or PTH, blood tests may be performed.
- Urine test may also be performed to measure calcium excretion.
HOW TO TREAT HYPOPARATHYROIDISM
- Therapy usually involves lifelong supplementation with calcium and very large amounts of vitamin D (which, along with PTH, is essential in maintaining proper blood levels of calcium).
- Severe muscle spasms (tetany) or convulsions may require hospitalization. Intravenous infusions of calcium may be given to provide temporary but immediate relief. Sedatives and anticonvulsants may also be administered.
- Regular periodic monitoring of blood calcium levels is essential.
WHEN TO CALL A DOCTOR
- Consult a doctor if you experience painful muscle spasms or cramps, or recurrent tingling, numbness, or burning sensations, especially if any of these symptoms occur in conjunction with other symptoms of hypoparathyroidism.
- Get immediate medical attention if breathing difficulty or seizures occur.
Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference
Simeon Margolis, M.D., Ph.D., Medical Editor
Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50
Updated by Remedy Health Media