In symptomatic hypercalcemia (usually above 11.5 mg/dl (≥ 2.9 mmol/l)), blood calcium levels should be lowered (see “Drug Therapy” below).
A hypercalcemic crisis (total serum calcium of > 3.5 mmol/l) is an emergency associated with the following symptoms: polyuria (increased urination), desiccosis (dehydration), hyperpyrexia (extreme fever: higher than 41 °C), cardiac arrhythmias, weakness and lethargy, and somnolence and even coma.