Approach to hypercalcemia

Hypercalcemia is a presentation commonly encountered in the clinical setting. Due to its vast differential diagnosis, a systematic approach is necessary when approaching patients with hypercalcemia. This article presents a simple, yet thorough approach to help clinicians determine the etiology of their patients' hypercalcemia. The main components of history taking, physical examination, and laboratory investigations for patients with hypercalcemia are highlighted. Emphasis is put on the importance of determining whether the hypercalcemia is associated with elevated or inappropriately normal parathyroid hormone (PTH) levels or not. The main etiologies of PTH-dependent hypercalcemia and PTH-independent hypercalcemia are explored. Primary hyperparathyroidism and hypercalcemia secondary to malignancy are highlighted as together, they make up 90% of hypercalcemia cases. A presentation of the management principles of hypercalcemia is also provided.