In diabetic ketoacidosis, which electrolyte abnormality is commonly observed?

• A. Hyponatremia
• B. Hypokalemia
• C. Hyperkalemia
• D. Hypercalcemia

Answer: (C)

In diabetic ketoacidosis, potassium balance behaves in a paradoxical way. The lack of insulin and the acidemia push potassium out of cells into the bloodstream, so serum potassium is often elevated or normal. At the same time, the body is losing potassium through diuresis and vomiting, so total body potassium is actually depleted. This combination—high or normal serum potassium with a true potassium deficit—makes hyperkalemia a commonly observed finding at presentation.

When treatment begins with fluids and insulin, potassium shifts back into cells, which can cause the serum level to fall rapidly unless potassium is replaced. So, although the blood potassium may look high initially, the patient still needs potassium management because bodily stores are depleted. Other electrolyte changes, like hyponatremia from osmotic effects of hyperglycemia, can occur, but the most characteristic and commonly seen disturbance is elevated potassium.