Providers should encourage their patients to drink when they are thirsty, as opposed to continuous hydration regardless of thirst, during physical activity to prevent a potentially fatal decrease in blood sodium level, according to an updated consensus statement on exercise-associated hyponatremia (EAH) published online ahead of print in the June issue of the Clinical Journal of Sport Medicine.


Lead author Tamara Hew-Butler, DPM, PhD, and colleagues met to revise previous recommendations after publicized reports of the death of two high school football players due to dilutional EAH. “Using the innate thirst mechanism to guide fluid consumption is a strategy that should limit drinking in excess and developing hyponatremia (low blood sodium), while providing sufficient fluid to prevent excessive dehydration,” they wrote in their recommendations. 


Sustained, excessive intake of water, sports drinks, or other fluids, which can exceed the body’s ability to eliminate fluids in the form of sweat and urine and dilute the body’s sodium level, is a major risk factor for EAH, according to the authors. As sodium levels decrease initially, individuals may not experience symptoms that warn them that something is wrong. When symptoms do occur, they may include headache, vomiting, and confusion or seizures, which are the result of cerebral edema. EAH can quickly become fatal without immediate treatment.