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Exercise-associated hyponatraemia — MRCEM SBA MCQ

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HardEnvironmental MedicineExercise-associated hyponatraemiaMRCEM SBA

A slow marathon runner in cool weather becomes confused and vomits at 35 km. He has been drinking at every station, gained weight and has swollen fingers. What is the most likely diagnosis?

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Correct answer: D — Exercise-associated hyponatraemia

Weight gain, high fluid intake and neurological symptoms suggest exercise-associated hyponatraemia. Giving more hypotonic fluid can worsen cerebral oedema. Sodium measurement and urgent medical care are required for symptomatic cases.

Reference: ACSM/IOC endurance medicine guidance