Which diagnosis is most likely when there is hyperglycemia, dehydration, metabolic acidosis with a high anion gap, and ketones are present?

• A. Hyperosmolar hyperglycemic state
• B. Hypoglycemia
• C. Lactic acidosis
• D. Diabetic ketoacidosis

Answer: (D)

This presentation is classic for diabetic ketoacidosis. When there isn’t enough insulin, the body can’t use glucose effectively and turns to fat for fuel. The liver converts those fats into ketone bodies, which accumulate in the blood and create a metabolic acidosis with a high anion gap. At the same time, high glucose levels spill into the urine, pulling water with it and causing dehydration through osmotic diuresis. The presence of ketones along with hyperglycemia and dehydration points directly to DKA.

Understanding the alternatives helps confirm the pattern: a hyperosmolar state also involves severe hyperglycemia and dehydration but typically has little or no ketone production and lacks the pronounced ketone-driven acidosis. Lactic acidosis can produce a high anion gap but isn’t characterized by ketones or significant hyperglycemia. Hypoglycemia would present with low blood glucose, not high.