Overview

Hyperhydration, also known as water intoxication or overhydration, occurs when endurance athletes consume excessive amounts of water, diluting blood sodium levels and leading to a potentially life-threatening condition called hyponatremia. While hydration is crucial during long events like marathons or triathlons, overcompensation can have serious consequences.

Causes

• Excessive water intake before, during, or after endurance events
• Inadequate electrolyte replacement (especially sodium)
• Misguided belief that “more water is always better”
• Prolonged physical exertion with high sweat loss
• Use of hypotonic fluids only, without electrolyte balance

Symptoms

• Nausea and vomiting
• Headache and confusion
• Muscle cramps or twitching
• Swelling in hands, feet, or brain (cerebral edema)
• Seizures or unconsciousness in severe cases

Diagnosis

• Blood tests showing low serum sodium (hyponatremia)
• Clinical signs during or after prolonged physical activity
• Evaluation of fluid intake history
• Neurological assessment if symptoms progress

Treatment

• Immediate fluid restriction
• Administration of oral or intravenous hypertonic saline
• Monitoring of electrolytes and neurological status
• Emergency care in cases of cerebral edema or seizures

Prognosis

• Good with prompt recognition and treatment
• Severe or untreated cases may lead to brain damage or death
• Most athletes recover fully if managed in time

Prevention & Control

• Educate athletes on proper hydration strategies
• Encourage electrolyte-based drinks, especially during long events
• Avoid forced or excessive drinking “just in case”
• Use thirst as a primary guide, not fixed drinking schedules
• Monitor weight before and after exercise to detect fluid imbalance