Hypercalcemia is a common life-threatening metabolic emergency in patients with tumors. Tumor invasion of bone tissue results in the release of calcium from bone tissue into the bloodstream. Hypercalcemia occurs when the mobilization of calcium from bone tissue exceeds the renal excretion threshold. Hypercalcemia occurs in approximately 15-20% of patients with tumors. Clinical manifestations: Systemic symptoms: dehydration, weight loss, food aversion, pruritus, thirst Neurological symptoms: fatigue, drowsiness, muscle weakness, hyporeflexia, seizures, loss of consciousness, coma Gastrointestinal symptoms: nausea, vomiting, constipation, intestinal obstruction Renal symptoms: polyuria, renal insufficiency Cardiac symptoms: atrial and ventricular arrhythmias, bradycardia Treatment: 1. Saline hydration diuresis to reduce calcium reabsorption. 2. 2. Application of bisphosphonates such as sodium iban phosphate, zolay phosphate, etc. 3. Calcitonin can rapidly inhibit bone resorption and reduce blood calcium within a few hours after administration. However, glucocorticoids should be applied at the same time as calcitonin, otherwise the body will quickly produce antibodies. 4.Puccamycin reduces bone resorption by decreasing the number and activity of osteolytic cells. It is usually injected once a week at 15-20μg/kg.