A state in which the PLASMA calcium concentration is significantly raised. The most important causes are HYPERPARATHYROIDISM, malignant bone disease and other (non-metastatic) cancers, and chronic renal failure. Less common causes include SARCOIDOSIS, MYELOMATOSIS, vitamin D overdosage (see APPENDIX 5: VITAMINS), hyperthyroidism (see THYROID GLAND, DISEASES OF), and immobilisation.
A general malaise and depression are common, with generalised muscular weakness, anorexia and vomiting. Disturbed renal function causes increased urine output and thirst, with calcium deposits eventually leading to renal stones. Primary bone disease may cause pain and weakness, with an increased incidence of fractures, and there may be gritty deposits of calcium in the eyes. Severe hypercalcaemia produces ANURIA, with confusion and COMA leading to death.
The patient is rehydrated and a diuretic (see DIURETICS) may be prescribed. Attention is focused on the underlying cause – usually a PARATHYROID ADENOMA or bone tumour – when BISPHOSPHONATES and surgical removal should produce complete clinical cure, provided that advanced renal disease is not already present.