Hypercalcaemia Health Dictionary

A hormone, produced by the THYROID GLAND, which is involved in the metabolism of bone. Acting to lower concentrations of CALCIUM and PHOSPHATES in the blood, calcitonin is given by injection in the treatment of some patients with HYPERCALCAEMIA (especially when associated with malignant disease). In severe cases of PAGET’S DISEASE OF BONE it is used mainly for pain relief, but also relieves some of the neurological complications such as deafness.... calcitonin

Overproduction of parathyroid hormone by the parathyroid glands that raises the calcium level in the blood (hypercalcaemia) by removing calcium from bones. This may lead to bone disorders, such as osteoporosis. To try to normalize the high calcium level, the kidneys excrete large amounts of calcium in the urine, which can lead to the formation of kidney stones (see calculus, urinary tract).

Hyperparathyroidism is most often caused by a small noncancerous tumour of 1 or more of the parathyroid glands. It may also occur when the glands become enlarged for no known reason. It usually develops after age 40 and is twice as common in women as in men.

Hyperparathyroidism may cause depression and abdominal pain. However, often the only symptoms are those caused by kidney stones. If hypercalcaemia is severe, there may be nausea, tiredness, excessive urination, confusion, and muscle weakness.

The condition is diagnosed by X-rays of the hands and skull and by blood tests.

Surgical removal of abnormal parathyroid tissue usually cures the condition.

If the remaining tissue is unable to produce enough parathyroid hormone, treatment for hypoparathyroidism is required.... hyperparathyroidism

Diabetes insipidus is a relatively rare condition and must be di?erentiated from DIABETES MELLITUS which is an entirely di?erent disease.

It is characterised by excessive thirst and the passing of large volumes of urine which have a low speci?c gravity and contain no abnormal constituents. It is either due to a lack of the antidiuretic hormone normally produced by the HYPOTHALAMUS and stored in the posterior PITUITARY GLAND, or to a defect in the renal tubules which prevents them from responding to the antidiuretic hormone VASOPRESSIN. When the disorder is due to vasopressin insu?ciency, a primary or secondary tumour in the area of the pituitary stalk is responsible for one-third of cases. In another one-third of cases there is no apparent cause, and such IDIOPATHIC cases are sometimes familial. A further one-third of cases result from a variety of lesions including trauma, basal MENINGITIS and granulomatous lesions in the pituitary-stalk area. When the renal tubules fail to respond to vasopressin this is usually because of a genetic defect transmitted as a sex-linked recessive characteristic, and the disease is called nephrogenic diabetes insipidus. Metabolic abnormalities such as HYPERCALCAEMIA and potassium depletion render the renal tubule less sensitive to vasopressin, and certain drugs such as lithium and tetracycline may have a similar e?ect.

If the disease is due to a de?ciency of vasopressin, treatment should be with the analogue of vasopressin called desmopressin which is more potent than the natural hormone and has less pressor activity. It also has the advantage in that it is absorbed from the nasal mucosa and so does not need to be injected.

Nephrogenic diabetes insipidus cannot be treated with desmopressin. The urine volume can, however, usually be reduced by half by a thiazide diuretic (see THIAZIDES).... diabetes insipidus

An abnormally large amount of calcium in the urine. It is the most common single cause of stones in the KIDNEYS in Britain. (See HYPERCALCAEMIA.)... hypercalciuria

A collection of disorders in which some part of the body’s internal chemistry (see METABOLISM; CATABOLISM) is disrupted. Some of these disorders arise from inherited de?ciencies in which a speci?c ENZYME is absent or abnormal, or does not function properly. Other metabolic disorders occur because of malfunctions in the endocrine system (see ENDOCRINE GLANDS). There may be over- or underproduction of a hormone involved in the control of metabolic activities: a prime example is DIABETES MELLITUS – a disorder of sugar metabolism; others include CUSHING’S SYNDROME; hypothyroidism and hyperthyroidism (see THYROID GLAND, DISEASES OF); and insulinoma (an insulin-producing tumour of the pancreas). The bones can be affected by metabolic disorders such as osteoporosis, osteomalacia (rickets) and Paget’s disease (see under BONE, DISORDERS OF). PORPHYRIAS, HYPERLIPIDAEMIA, HYPERCALCAEMIA and gout are other examples of disordered metabolism.

There are also more than 200 identi?ed disorders described as inborn errors of metabolism. Some cause few problems; others are serious threats to an individual’s life. Individual disorders are, fortunately, rare – probably one child in 10,000 or 100,000; overall these inborn errors affect around one child in 1,000. Examples include GALACTOSAEMIA, PHENYLKETONURIA, porphyrias, TAY SACHS DISEASE and varieties of mucopolysaccharidosis, HOMOCYSTINURIA and hereditary fructose (a type of sugar) intolerance.... metabolic disorders

The body’s most abundant mineral, essential for cell function, muscle contraction, the transmission of nerve impulses, and blood clotting. Calcium phosphate is the hard basic constituent of teeth and bones. Dietary sources of calcium include dairy products, eggs, and green, leafy vegetables. Calcium uptake is facilitated by vitamin D.

The body’s calcium levels are controlled by parathyroid hormone and calcitonin.

Abnormally high levels in the blood (hypercalcaemia) or abnormally low levels (hypocalcaemia) may seriously disrupt cell function, particularly in muscles and nerves. (See also mineral supplements.)... calcium

A rare type of hypercalcaemia accompanied by alkalosis and kidney failure. The syndrome is due to excessive, long-term intake of calciumcontaining antacid drugs and milk. It is most common in people with a peptic ulcer and associated kidney disorders. Symptoms include weakness, muscle pains, irritability, and apathy. Treatment is to reduce milk and antacid intake.... milk–alkali syndrome

pl. n. a class of drugs that inhibit the resorption of bone by blocking the action of *osteoclasts. This property makes them useful for treating certain bone disorders, such as Paget’s disease and osteoporosis, as well as malignant disease – both in terms of pain relief and in treating hypercalcaemia due to cancer. There is a risk of *osteonecrosis of the jaw in patients receiving bisphosphonates for cancer. This risk is increased by tooth extraction. Bisphosphonates include *alendronic acid, etidronate, *pamidronate disodium, risedronate, clodronate, and *zoledronic acid.... bisphosphonates

n. a drug that mimics the action of calcium in the body by activating the calcium-sensing cell receptors and thus reduces the level of *parathyroid hormone. It is used in the treatment of secondary *hyperparathyroidism in advanced kidney failure and also for reducing the level of *hypercalcaemia in parathyroid carcinoma. It is taken orally. Trade name: Mimpara.... cinacalcet

the calcification of injured or necrotic tissue in the absence of systemic *hypercalcaemia. Dystrophic calcification is a characteristic feature in some cancers of the breast, ovary, and thyroid gland. Compare metastatic calcification.... dystrophic calcification

A rare disease of unknown cause in which there is inflammation of tissues throughout the body, especially the lymph nodes, lungs, skin, eyes, and liver. It occurs mainly in young adults.

Symptoms do not always occur, but when they do, they include fever, generalized aches, painful joints, and painful, bloodshot eyes. Sarcoidosis may also cause enlargement of the lymph nodes, breathlessness, erythema nodosum, a purplish facial rash, and areas of numbness. Possible complications include hypercalcaemia, which may damage the kidneys, and pulmonary fibrosis.

Treatment of sarcoidosis is not always needed.

Most people recover completely within 2 years, with or without treatment, but some develop a persistent, chronic form of the disease.

Corticosteroids are given to treat persistent fever or erythema nodosum, to prevent blindness in an affected eye, and to reduce the risk of lung damage.... sarcoidosis

The collective term for a group of substances that help to regulate the balance of phosphate and calcium in the body, aid calcium absorption in the intestine, and promote strong bones and teeth.

Good sources include oily fish, liver, and egg yolk; vitamin D is also added to margarines. In the body, vitamin D is synthesized by the action of ultraviolet light on a particular chemical in the skin.

Deficiency may occur in people with a poor diet, in premature infants, and in those deprived of sunlight. It can also result from malabsorption. Other causes include liver or kidney disorders and some genetic defects. Prolonged use of certain drugs, such as phenytoin, may also lead to deficiency. Deficiency in young children causes rickets; long-term deficiency in adults leads to osteomalacia.Excessive intake of vitamin D may lead to hypercalcaemia and abnormal calcium deposits in the soft tissues, kidneys, and blood vessel walls.

In children, it may cause growth retardation.... vitamin d

defects of kidney function related to a high serum calcium, irrespective of cause. Impaired urine-concentrating ability and reduction in glomerular filtration rate are common features. Histologically, calcific deposits in the kidneys (*nephrocalcinosis) may be seen in cases of long-standing hypercalcaemia.... hypercalcaemic nephropathy

n. the presence in the blood of an abnormally low concentration of calcium. See tetany. Compare hypercalcaemia.... hypocalcaemia

disease of the *tubulointerstitium of the kidney. Acute interstitial nephritis (AIN) represents in many cases an allergic reaction to drugs (especially ampicillin, cephalexin, NSAIDs, allopurinol, and frusemide). AIN can also be associated with acute infections and autoimmune disease. Thirst and polyuria may be prominent, and renal function severely affected. In allergic cases, the use of steroids hastens recovery after the allergen has been removed. Chronic interstitial nephritis (CIN) is associated with progressive scarring of the tubulointerstitium, often with lymphocyte infiltration. Primary causes of CIN include gout, radiation nephropathy, sarcoidosis, *analgesic nephropathy, reflux nephropathy, chronic hypokalaemia and hypercalcaemia, and *Aristolochia-associated nephropathies. Management of CIN involves removal of the precipitating cause, where identified, and control of hypertension.... interstitial nephritis

the calcification of otherwise normal tissues in patients with *hypercalcaemia. Compare dystrophic calcification.... metastatic calcification

a *bisphosphonate drug used to treat malignant *hypercalcaemia, breast cancer that has spread to the bones, and Paget’s disease. Side-effects include flulike symptoms, nausea, and vomiting.... pamidronate disodium

(PTH-RP) a protein that is secreted by certain malignant tumours and is the main cause of malignant *hypercalcaemia. PTH-RP, which has effects similar to *parathyroid hormone, stimulates generalized bone resorption and excessive calcium reabsorption in the kidney tubules. It is most commonly produced by lung tumours, squamous-cell carcinomas of other organs, melanomas, and tumours of the breast, liver, pancreas, bladder, and prostate.... parathyroid hormone-related protein

n. a drug used in the treatment of *breast cancer: it binds with hormone receptors in the tumour to inhibit the effect of oestrogens (see anti-oestrogen; selective (o)estrogen receptor modulator). Tamoxifen is also used to treat female infertility as it induces ovulation. Side-effects include nausea, vaginal bleeding, facial flushing, tumour pain, and hypercalcaemia.... tamoxifen

(NDI) a condition characterized by *polyuria and *polydipsia and due to failure of the renal tubules to respond, or to respond fully, to *vasopressin. One form of congenital NDI is caused by an X-linked (see sex-linked) dominant mutation of the gene encoding the vasopressin V2 receptor. A rarer form of congenital NDI is an autosomal recessive condition associated with genetic mutations in the gene encoding AQP-2 water channels (see aquaporin). Acquired NDI is much commoner than the congenital form and usually less severe. It is present in most patients with advancing chronic renal failure, is a feature of certain electrolyte disorders (hypokalaemia, hypercalcaemia), and can complicate chronic lithium treatment.... nephrogenic diabetes insipidus

a hereditary condition, caused by a defect (a *deletion) in chromosome 7, marked by a characteristic ‘elfin’ facial appearance (including large eyes, a wide mouth, and small chin), *hypercalcaemia, short stature, learning disabilities, and *aortic stenosis. Most affected children are highly sociable and have unusual conversational ability, using a rich and complex vocabulary. The condition can be diagnosed prenatally. [J. C. P. Williams (20th century), British physician]... williams syndrome

(zolendronate) a *bisphosphonate drug that is used to treat Paget’s disease and malignant *hypercalcaemia and is also establishing a role in treating bone metastases, both in terms of symptom relief and preventing bone fractures.... zoledronic acid