Calcium homeostasis is primarily controlled by parathyroid hormone and hydroxylated vitamin D. Parathyroid hormone is produced by the parathyroid gland and vitamin D is either indigested in the diet or synthesized in the skin via exposure to sunlight. The mechanisms of action are outlined in the diagram below:

Hypercalcaemia can result in the following signs and symptoms (beyond the classical ‘stones, bones, abdominal groans and psychic moans…’)
  • Polyuria
  • Polydipsia
  • Renal stones
  • Nausea and vomiting
  • Anorexia
  • Constipation
  • Confusion
  • Psychotic behaviour
  • Headache
  • Bone pain
  • Hypertension (rare)

Causes of hypercalaemia:

Malignant disease can cause hypercalcaemia due to:
  • Bone involvement – boney mets - ‘bronchus, breast, byroid, brostate and bidney’ (AKA bronchus, breast, thyroid, prostate and kidney) and myeloma
  • Parathyroid Hormone related Peptide (PTHrP) produced by tumour, especially squamous cell tumours such as lung, oesophagus and breast, renal and bladder tumours.

ECG changes seen in hypercalcaemia can include: short QT, bradycardia, bundle branch block or AV block

Treatment is:
  • Treat cause
  • Normal saline
  • Pamidronate
Small print gem: Hypercalcaemia increases sensitivity to digoxin

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Secret collector of interesting anonymised ECGs. Fan of the Bath Photomarathon. Lover of cream teas. [Sarah Hudson] (Your Picture)