This article discusses hypercalcemia, emphasizing its causes, diagnosis, and management. It highlights that serum calcium levels reflect water and protein-bound calcium, with ionized calcium being the active form. Common causes include primary hyperparathyroidism, malignancy, kidney disease, vitamin D toxicity, and systemic illnesses. Clinical signs often relate to neuromuscular and cardiovascular disturbances, especially at severe levels. Diagnosis involves measuring serum and ionized calcium, assessing underlying conditions, and differentiating between parathyroid-dependent and independent causes. Treatment focuses on addressing the primary cause, dietary modifications, or surgical intervention, with careful monitoring to prevent complications.