Dilutional hyponatremia is described as water poisoning.

• A. Water poisoning which leads to brain edema, brain stem herniation, and death
• B. Hypernatremia due to water loss
• C. Hypokalemia
• D. Acid-base imbalance

Answer: (A)

Excess free water relative to solutes lowers serum sodium and plasma osmolality, so water moves into brain cells. This causes cerebral edema, which raises intracranial pressure and can lead to brain herniation and death. That’s why dilutional hyponatremia is described as water poisoning—the uncontrolled water overload directly drives dangerous brain swelling and potential fatal outcomes.

Hypernatremia from water loss would be the opposite problem (too much solute or not enough water), not dilutional hyponatremia. Hypokalemia is a potassium deficiency and not the defining feature here. Acid-base imbalance can occur in severe cases but is not the hallmark risk; the critical danger in dilutional hyponatremia is brain edema with possible brainstem herniation and death.