A seemingly healthy, robust guy, in the peak of his health, runs 10 km in the sweltering heat. After becoming dehydrated, he tries to recover by drinking nearly five litres of plain water in less than an hour. Instead of helping, the excessive and rapid intake overwhelms the body's ability to maintain a healthy electrolyte balance.

Soon afterward, he develops a severe headache and decides to lie down, assuming rest will make him feel better. However, his condition deteriorates rapidly. The sudden overload of water causes a dangerous drop in blood sodium levels, a condition known as hyponatremia. As sodium levels fall, water moves into brain cells, leading to swelling of the brain. This can trigger confusion, vomiting, seizures, loss of consciousness, and, in severe cases, death. In this instance, he suffers a major seizure while resting and does not survive.

Taking to X, internal medicine expert Dr Priyam Bordoloi explained what happened to the death of a seemingly healthy man. He explained the phenomenon of Acute Water Intoxication (Severe Dilutional Hyponatremia). As the man was sweating profusely, he lost water and sodium. . This dramatically diluted the sodium concentration in his bloodstream, leading to a dangerous condition called acute hyponatremia.

As blood sodium levels dropped, water moved into the body's cells to restore the balance of fluids. While many tissues can tolerate some swelling, the brain cannot. Brain cells are enclosed within the rigid skull, leaving little room for expansion. As these cells absorbed excess water, pressure inside the skull rose rapidly, causing cerebral edema, or swelling of the brain. This increased pressure can lead to severe headaches, confusion, vomiting, seizures, loss of consciousness, brain herniation, and, if not treated immediately, death.

Could he have been saved?

In many cases, yes. Dr Bordoloi explained that scute hyponatremia is a medical emergency, and prompt treatment can be lifesaving. If the person had reached an emergency department quickly, doctors could have administered intravenous hypertonic saline (3% sodium chloride). This concentrated saline solution helps raise blood sodium levels and draws excess water out of swollen brain cells, reducing pressure within the skull. Careful monitoring is essential because sodium levels must be corrected at an appropriate rate to avoid additional neurological complications.

How can this be prevented?

The doctor warned against drinking very large amounts of plain water in a short period, especially after prolonged exercise or heavy sweating.

Replace both fluids and electrolytes after strenuous activity. Oral rehydration solutions (ORS), electrolyte drinks, or naturally electrolyte-rich options such as coconut water can help replenish sodium and other minerals lost through sweat.

Drink according to thirst and spread fluid intake over time rather than consuming excessive amounts all at once.
If symptoms such as severe headache, confusion, repeated vomiting, muscle cramps, or seizures develop after heavy water intake or prolonged exercise, seek emergency medical care immediately, as these may be signs of life-threatening hyponatremia.