aetiology of hypercalcaemia

Last reviewed 04/2022

The common causes of hypercalcaemia which accounts for about 90% of cases are due to primary hyperparathyroidism and malignancy:

  • primary hyperparathyroidism – commonest cause in the community (1), accounts for 80% of cases and is more important in the young
  • malignancy accounts for 20-30% of cases (1) and is frequently accompanied by hypoalbuminaemia:
    • suggested by rapidly increasing hypercalcaemia (1)
    • metastases with osteolytic deposits e.g. breast
    • osteoclast activating factors e.g. multiple myeloma
    • ectopic parathyroid hormone like peptide e.g. hypernephroma, ovarian tumour, bronchial carcinoma
    • 10-15% of hypercalcaemia caused by malignancy have associated hyperparathyroidism (2)

Rarer causes of hypercalcaemia include:

  • increased extrarenal synthesis of calcitriol in chronic granulomatous disease:
    • sarcoidosis
    • pulmonary tuberculosis
    • berylliosis
  • Addison's disease
  • Paget's disease with bed rest
  • immobilisation - especially in adolescence when bone turnover is increased
  • vitamin A and/or D toxicity
  • drugs:
    • thiazide diuretics
    • lithium
  • thyrotoxicosis:
    • usually mild and accompanied by hypercalciuria
    • due to increased bone turnover
  • familial hypocalciuric hypercalcaemia
  • tertiary hyperparathyroidism
  • milk alkali syndrome
  • multiple endocrine neoplasia (MEN) (2,3)

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