What does a positive ketone test signify on dipstick?

• A. Glycosuria due to hyperglycemia
• B. Fat metabolism issues such as diabetes ketoacidosis or fasting.
• C. Bilirubin from liver disease
• D. Hematuria due to urinary stones

Answer: (B)

A positive urine ketone dipstick means ketone bodies are present in the urine, reflecting increased fat breakdown when carbohydrate supply is limited or not used properly. This commonly occurs during fasting or starvation, and in diabetes mellitus when insulin is deficient, leading to diabetic ketoacidosis. The test on the dipstick detects acetoacetate through a nitroprusside reaction, so a positive result indicates ketosis due to fat metabolism rather than issues with glucose, bilirubin, or red blood cells. In practice, ketonuria supports checking for states like DKA or prolonged fasting, alongside glucose and acid-base assessment, since ketosis can accompany dangerous metabolic conditions or simply occur with prolonged fasting.