Hypoparathyroidism Classification and external resources ICD-10 E20, E89.2, P71.4 ICD-9 252.1 DiseasesDB 6490 eMedicine med/1131 emerg/276 ped/1125 MeSH D007011
Hypoparathyroidism is decreased function of the parathyroid glands, as evidenced by decreased levels of parathyroid hormone (PTH). PTH is required for maintaining adequate calcium levels in the blood, and low PTH levels can therefore lead to hypocalcaemia (low calcium levels), which can have potentially serious consequences.
Signs and symptoms
- Tingling lips, fingers, and toes
- Muscle cramps
- Pain in the face, legs, and feet
- Abdominal pain
- Dry hair
- Brittle nails
- Dry, scaly skin
- Weakened tooth enamel (in children)
- Muscle spasms called tetany (can lead to spasms of the larynx, causing breathing difficulties)
- Convulsions (seizures)
- Tetanic contractions
Additional symptoms that may be associated with this disease include:
- Painful menstruation
- Hand or foot spasms
- Decreased consciousness
- Delayed or absent tooth formation
- Calcification of the basal ganglia due to increased phosphorus levels driving calcium into the brain tissue.
In contrast to hyperparathyroidism (hyperfunction of the parathyroids), hypoparathyroidism has been shown to result in increased calcium deposition into bones, accompanied by increased bone density, but at the same time, a higher fragility status, believed to result from faulty bone remodeling in the absence of parathyroid hormone activity. Some reports have described a high occurrence, as high as 50%, of vetebral deformities amongst patients with hypoparathyroidism.
Diagnosis is by measurement of calcium, serum albumin (for correction) and PTH in blood. PTH degrades rapidly at ambient temperatures and the blood sample therefore has to be transported to the laboratory on ice.
If necessary, measuring cAMP (cyclic AMP) in the urine after an intravenous dose of PTH can help in the distinction between hypoparathyroidism and other causes.
Differential diagnoses are:
- Pseudohypoparathyroidism (normal PTH levels but tissue insensitivity to the hormone, associated with mental retardation and skeletal deformities) and pseudopseudohypoparathyroidism (sic).
- Vitamin D deficiency or hereditary insensitivity to this vitamin (X-linked dominant).
- Kidney disease
- Medication: steroids, diuretics, some antiepileptics.
Other tests include ECG for abnormal heart rhythms, and measurement of blood magnesium levels.
Hypoparathyroidism can have a number of divergent causes:
- Removal of or trauma to the parathyroid glands in thyroid surgery (thyroidectomy) or other neck surgeries is a recognized cause. It is now uncommon, as surgeons generally can spare them during procedures after identifying them. In a small percentage of cases, however, they can become traumatized during surgery and/or their blood supply can be compromised. When this happens the parathyroids may cease functioning for a while or stop altogether.
- Autoimmune invasion and destruction is the most common non-surgical cause. It can occur as part of autoimmune polyendocrine syndromes.
- Hemochromatosis can lead to iron accumulation and consequent dysfunction of a number of endocrine organs, including the parathyroids.
- Absence or dysfunction of the parathyroid glands is one of the components of chromosome 22q11 microdeletion syndrome (other names: DiGeorge syndrome, Schprintzen syndrome, velocardiofacial syndrome).
- Magnesium deficiency
- DiGeorge syndrome, a disease in which hypoparathyroidism can occur due to a total absence of the parathyroid glands at birth. Familial hypoparathyroidism occurs with other endocrine diseases, such as adrenal insufficiency, in a syndrome called type I polyglandular autoimmune syndrome (PGA I).
- Some very rare diseases
- Idiopathic (of unknown cause), occasionally familial
Severe hypocalcemia, a potentially life-threatening condition, is treated as soon as possible with intravenous calcium (e.g. as calcium gluconate). Generally, a central venous catheter is recommended, as the calcium can irritate peripheral veins and cause phlebitis.
Long-term treatment of hypoparathyroidism is with calcium and vitamin D3 supplementation (D1 is ineffective in the absence of renal conversion). Teriparatide, a synthetic form of PTH (presently registered for osteoporosis) might become the treatment of choice for PTH supplementation, although further studies are awaited.
In the event of a life-threatening attack of low calcium levels or tetany (prolonged muscle contractions), calcium is administered by intravenous (IV) infusion. 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 as often as four times a day.
- Tetany can lead to a blocked airway, requiring a tracheotomy.
- Stunted growth, malformed teeth, and slow mental development can occur if hypoparathyroidism develops in childhood.
- Overtreatment with vitamin D and calcium can cause hypercalcemia (high blood calcium) and sometimes interfere with kidney function.
- There is an increased risk of pernicious anemia, Addison's disease, cataract development, and Parkinson's disease.
- Hurd, Robert (2006-10-25). "Hypoparathyroidism". Medical Encyclopedia. Medline Plus. http://www.nlm.nih.gov/medlineplus/ency/article/000385.htm. Retrieved 2007-11-02.
- ^ p493, Goljan, Edward F. (2009-08-03). Rapid Review Pathology. Mosby. ISBN 0323068626, 9780323068628.
Endocrine pathology: endocrine diseases (E00–E35, 240–259) Pancreas/
pituitary axesHypothalamusPituitaryThyroidEndemic goitre · Toxic nodular goitre · Toxic multinodular goiter
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Look at other dictionaries:
hypoparathyroidism — noun Date: 1910 deficiency of parathyroid hormone in the body; also the resultant abnormal state marked by low serum calcium and a tendency to chronic tetany … New Collegiate Dictionary
hypoparathyroidism — ▪ pathology inadequate secretion of parathyroid hormone, usually caused by accidental surgical removal of large amounts of parathyroid tissue (during thyroid surgery) or, less frequently, by defective action of the parathyroid gland. This… … Universalium
hypoparathyroidism — noun deficiency of parathyroid hormone. See Also: pseudopseudohypoparathyroidism … Wiktionary
hypoparathyroidism — A condition due to diminution or absence of the secretion of the parathyroid hormones, with low serum calcium and tetany, and sometimes with increased bone density. SEE ALSO: pseudohypoparathyroidism. SYN: parathyroid insufficiency … Medical dictionary
hypoparathyroidism — [ˌhʌɪpəʊˌparə θʌɪrɔɪdɪz(ə)m] noun Medicine diminished concentration of parathyroid hormone in the blood, causing deficiencies of calcium and phosphorus compounds. Derivatives hypoparathyroid adjective … English new terms dictionary
hypoparathyroidism — hy·po·par·a·thy·roid·ism … English syllables
hypoparathyroidism — n. subnormal activity of the parathyroid glands, causing a fall in the blood concentration of calcium and muscular spasms (see tetany) … The new mediacal dictionary
hypoparathyroidism — noun inadequate secretion of parathyroid hormone resulting in abnormally low levels of calcium in the blood • Ant: ↑hyperparathyroidism • Hypernyms: ↑glandular disease, ↑gland disease, ↑glandular disorder, ↑adenosis … Useful english dictionary
Гипопаратиреоз (Hypoparathyroidism) — недостаточность функции паращитовидной железы, приводящая к уменьшению содержания ионов кальция в крови и развитию мышечных спазмов (см. Тетания). (Типичное проявление сильное сгибание рук в запястьях ред.) Источник: Медицинский словарь … Медицинские термины
parathyroid insufficiency — hypoparathyroidism … Medical dictionary