Hypercalcemia: A condition describing too much calcium in the blood. Hypercalcemia can result from excess bone resorption in patients with multiple myeloma. Hypercalcemia is usually treated on an emergency basis using intravenous fluids plus drugs that reduce bone destruction and treat multiple myeloma. Signs and symptoms may include loss of appetite, nausea, thirst, fatigue, muscle weakness, restlessness, and confusion. Calcium elevation >10 mg/dL is a CRAB criterion that indicates end-organ damage associated with active multiple myeloma