Hyponatremia, defined as a serum sodium < 135 mmol/l, is a common electrolyte disorder with a reported incidence of up to 30% in hospitalized patients [1–3]. Profound, symptomatic hyponatremia with a serum sodium < 125 mmol/l is less common, with a reported incidence of 1–3%, but bears the risk of life-threatening complications such as seizure, coma or death [2–4]. Profound hyponatremia is more likely to be promptly corrected by physicians, whereas mild to moderate hyponatremia in asymptomatic patient often remains unaddressed [1,3,5].
