Exercise-associated hyponatremia Exercise-associated hyponatremia Exercise-associated hyponatremia, or EAH, is a fluid-electrolyte disorder caused by a decrease in sodium levels (hyponatremia) during or up to 24 hours after prolonged physical activity. This disorder can develop when marathon runners or endurance event athletes drink more fluid, usually water or sports drinks, than their kidneys can excrete. This excess water can severely dilute the level of sodium in the blood needed for organs, especially the brain, to function properly. The incidence of EAH in athletes has increased in recent years, especially in the United States, as marathon races and endurance events have become more popular.
Hyponatremia saline is only recommended in those with significant symptoms and occasionally those in whom the condition was of rapid onset. Low volume hyponatremia is typically treated with intravenous normal saline. SIADH is typically treated with fluid restriction while high volume hyponatremia is typically treated with both fluid restriction and a diet low in salt. Correction should generally be gradual in those in whom the low levels have been present for more than two days. Hyponatremia occurs in about 20% of those admitted to hospital and 10% of people during or after an endurance sporting event. Among those in hospital, hyponatremia