Causes
Parathyroid gland tumours, kidney disease, certain tumours, complications following thyroid surgery, nutritional imbalances.
Diagnosis
Blood tests that detect the abnormal calcium level, plus hormone tests (PTH) and imaging to locate the underlying cause.
Treatment
Depends on the cause: surgery if there is a parathyroid tumour, supplements or medication to correct the calcium, and treatment of the underlying disease.
Prevention
Difficult to prevent. Routine blood tests can detect abnormal calcium levels before they cause serious symptoms.

