Answer is A (Acute renal failure): Renal insufficiency is associated with hyperphosphatemia due to impaired renal phosphate excretion. Acute renal failure: 'Mild Hyperphosphatemia is an almost invariable complication of Acute Renal Failure. Severe hyperphosphatemia may develop in highly catabolic patients or following rhabdomyolysis, hemolysin or tumor lysis.' -- Harrison 16th / 1650 Diabetic ketoacidosis or Metabolic acidosis from any other causes may be associated with hyperphosphatemia from transcellular phosphatic shifts. However resolving phases of diabetic ketoacidosis are associated with hypophosphatemia and not hyperphosphatemia. This is a result of insulin therapy for diabetic ketoacidosis. Causes of hyperphosphatemia Causes of hypophosphatemia Metabolic acidosis Insulin therapy of diabetic ketoacidosis or prolonged (Lactic acidosis / Diabetic Ketoacidosis) hyperglycemia. Laboratory values in DKA / Harrison 6th / 323 - 324 Phosphate values are : decreased (large changes occurs during treatment of DKA Also note that total body stores of phosphorus (Also potassium, sodium, chloride, magnesium) are reduced in DKA, but are not accurately reflected by their levels (serum values may be increased) because of dehydration and hyperglycemia. -- Harrison Respiratory alkalosis is associated with hypophosphatemia by causing intracellular shift of phosphorus into cells. Hypophosphatemia * Hyperphosphatemia Metalbolic alkalosis * Metabolic acidosis Respiratory alkalosis * Respiratory acidosis Chronic alcoholism / Alcoholism is known to cause hypophosphatemia. -- Harrison 16th / 881 Severe hypophosphatemia is common and multifactorial in alcoholic patients. Chronic alcohol use results in a decrease in the renal threshold of phosphate excretion.' -- CMDT Patients with COPD and Asthma commonly have hypophosphatemia. This is attributed to xanthine derivatives causing shifts of phosphate intracellularly and the phosphaturic effects of beta -- adrenergic agonists, loop diuretics, xanthine derivatives and coicosteroids. -- CMDT 2006 / 88