Hyperphosphatemia

An abnormally elevated concentration of inorganic phosphate in the blood (>1.45 mmol/L or >4.5 mg/dL), often associated with secondary hypocalcemia. Possible causes are impaired renal phosphate excretion, hypoparathyroidism, massive phosphate load (phosphate-containing laxatives or enemas), vitamin D toxicity, cell breakdown (rhabdomyolysis, tumor lysis syndrome), and diabetic ketoacidosis.