Hypophosphataemia in confused half‐marathon runners: A report of two cases

Severe hypophosphataemia may occur in long distance runners presenting to Accident & Emergency (A&E) department with exertional heat illness. Case presentation: A 46‐year‐old man who collapsed in half marathon race was found to have raised body temperature (38.8°C) and confused with memory loss in the Accident & Emergency department. His amnesia was persistent even after his body temperature was normalized. He was found to have severe hypophosphataemia (0.21 mmol/L; reference range: 0.74 ‐ 1.4 mmol/L). He had a neurological recovery after phosphate replacement. Another 45‐year‐old female half marathon runner was found to have moderate hypophosphataemia (0.5 mmol/L) co‐presenting with exertional heat illness. Discussion: Moderate to severe hypophosphataemia complicated the clinical picture of the two cases presented with exertional heat illness. Causes of hypophosphataemia in runners are multifactorial. Conclusion: Emergency physician should be alert of profound hypophosphataemia as a complication in heat exertional illness.