Background: Hypercalcemic crisis, generally caused by malignancy or primary hyperparathyroidism, is a life-threatening emergency that can result in multi-organ failure. Lowering the patient’s calcium level immediately and determining the correct etiology are essential.
Case Report: We report a case of hypercalcemic crisis with a novel etiology. A 66-year-old male presented to the emergency room in cardiac arrest with a ventricular arrhythmia after being discovered submerged in an indoor public bath. He underwent cardioversion and was emergently intubated. Computed tomography showed bilateral pulmonary edema, suspected from water aspiration. Laboratory data revealed severe hypercalcemia and mild hypernatremia. Following three days of continuous hemodiafiltration, serum Ca decreased to and remained within normal limits. We concluded the etiology of hypercalcemia was absorption of Ca resulting from aspirated water.
Conclusions: Near drowning can be a cause of hypercalcemic crisis. For cases of near drowning, it is important to investigate the source of the aspirated water and consider electrolyte abnormalities in the diagnosis.

Keywords: Hypercalcemia, Near-drowning, emergency, Hot Springs