Symptoms of hypercalcemia include fatigue, depression, confusion, anorexia, thirst, constipation, increased urination. It can cause electrocardiogram (ECG) mainly short QT interval, and electroencephalogram (EEG) changes, leading to ECG and EEG arrhythmias. Thus, severe hypercalcemia is a medical emergency, because it can cause cardiac arrest and epilepsy. In aging patients, hypercalcemia may be a manifestation of primary hyperpaathyroidism, cancer, prolonged bed resting, vitamine D intoxication, etc. Confirmatory diagnosis of primary hyperparathyroidism can be established by the presence of elevated parathormone levels, neck ultrasound and parathyroid CT scan and scintigraphy. Parathyroid adenomas respond well to surgical treatment. Medical treatment includes cinacalcet, a calcium sensing receptor agonist, that reduces PTH adenoma secretion and hypercalcemia. Biphosphonates and other bone-protective drugs can also help to control hypercalcemia.