Chronic hypercalcaemia is a condition characterised by persistently elevated serum calcium levels, typically above 2.6 mmol/L, which can lead to various physiological disturbances. It is clinically significant as it can cause symptoms such as renal impairment, neurological changes, and cardiovascular issues, necessitating prompt diagnosis and management. A key association is primary hyperparathyroidism, where excessive parathyroid hormone secretion leads to increased calcium release from bones.