Which abnormality is most commonly noted in bulimia nervosa due to purging?

• A. Metabolic acidosis
• B. Hypokalemia
• C. Hyperalbuminemia
• D. Amenorrhea

Answer: (B)

Purging in bulimia nervosa frequently leads to electrolyte disturbances, with low potassium being the most common finding. Vomiting causes loss of gastric fluids and volume depletion, which triggers mechanisms that drive potassium out of the bloodstream: the resulting metabolic alkalosis shifts potassium into cells, and aldosterone-driven renal potassium wasting from volume contraction further lowers serum potassium. This combination makes hypokalemia a hallmark of purging-type eating disorders and helps explain associated symptoms like weakness, cramps, and potential cardiac rhythm issues. Metabolic alkalosis often accompanies this picture, but among the options, low potassium best captures the typical consequence of purging. The other choices don’t fit as well: metabolic acidosis is not expected with purging, hyperalbuminemia is not a typical result, and while amenorrhea can occur in eating disorders, it’s not a direct, most common consequence of purging itself.