Table 1.

Aetiology of hypercalcaemia.

Elevated or inappropriately normal PTH	Suppressed PTH
Primary hyperparathyroidism (PHPT)	Malignancy
Solitary adenoma	Humoral mediators (e.g. PTH-related protein)
Multiple adenoma	Vitamin D mediated
Parathyroid hyperplasia	Multiple myeloma
Parathyroid carcinoma	Lytic bone metastases
Tertiary hyperparathyroidism (THPT)
Advanced chronic kidney disease (CKD)	Drug induced
Severe vitamin D deficiency	Calcium supplementation
Malabsorption of calcium (e.g. celiac disease)	Milk-alkali syndrome
	Vitamin D intoxication
	Vitamin A intoxication
	Thiazide diuretics
	Lithium therapy
Miscellaneous
Familial hypocalciuric hypercalcaemia (FHH)	Endocrinopathies
	Thyrotoxicosis
	Addison's disease
	Phaeochromocytoma
	VIPoma
	Immobilization
	Granulomatous disorders including sarcoidosis

PTH, parathyroid hormone.