Differential Diagnosis: Hypophosphatemia

Following are differential diagnoses, listed in order of likelihood, for patients presented with hypophosphatemia.

• Transcellular shifts

  • Diabetes mellitus, particularly diabetic ketoacidosis, following insulin therapy (common)

  • Respiratory alkalosis due to hyperventilation caused by hypoxia, stress, anxiety, salicylate toxicity, CNS disease, fever, heat stroke, sepsis, and/or gram-negative infections

  • Refeeding syndrome

• Decreased absorption

  • Vomiting/diarrhea, particularly secondary to severe malabsorptive disease

  • Anorexia

  • Vitamin D deficiency

  • Low-phosphorus diet

  • Overdose of phosphate-binding antacids 

  • Steatorrhea

  • Following significant intestinal resection

• Increased renal excretion

  • Diabetes mellitus

  • Diuretics

  • Corticosteroids

  • Hyperadrenocorticism

  • Hypercalcemia of malignancy

  • Primary hyperparathyroidism

  • Renal tubular disorder (eg, Fanconi syndrome)

  • Hyperaldosteronism

  • Increased phosphatonins (eg, following renal transplantation [cats])

  • Eclampsia

  • Recovery from hypothermia

  • Following hepatic resection

• Miscellaneous

  • Hepatic lipidosis (cats)

• Pseudohypophosphatemia

  • Paraproteinemia