Which symptom would you expect in hyponatremia due to neurological effects?

• A. Confusion
• B. Hypertonia
• C. Flushing
• D. Hypertension

Answer: (A)

When sodium levels drop, extracellular osmolality falls and water moves into brain cells, causing cerebral edema. This swelling disrupts neuronal signaling and brain function, so confusion becomes a common neurologic symptom in hyponatremia. The more rapid or severe the drop, the more pronounced the mental status changes, and seizures or coma can occur in extreme cases. The other options aren’t typical neurologic manifestations of hyponatremia: hypertonia is increased muscle tone, flushing is a skin-flush response, and hypertension isn’t a characteristic sign driven by low sodium in the brain.