A ketone urine test measures the amount of ketones in the urine.
Ketone bodies - urine; Urine ketones
How the Test is Performed
Urine ketones are usually measured as a "spot test." This is available in a test kit that you can buy at a drug store. The kit contains dipsticks coated with chemicals that react with ketone bodies. A dipstick is dipped in the urine sample. A color change indicates the presence of ketones.
This article describes the ketone urine test that involves sending collected urine to a lab.
A clean-catch urine sample is needed. The clean-catch method is used to prevent germs from the penis or vagina from getting into a urine sample. To collect your urine, the health care provider may give you a special clean-catch kit that contains a cleansing solution and sterile wipes. Follow instructions exactly so that the results are accurate.
How to Prepare for the Test
You may have to follow a special diet. Your health care provider may tell you to stop taking medicines that may affect the test.
How the Test will Feel
The test involves only normal urination. There is no discomfort.
Why the Test is Performed
Ketones build up when the body needs to break down fats and fatty acids to use as fuel. This is most likely to occur when the body does not get enough sugar or carbohydrates.
Ketone testing is most often done if you have type 1 diabetes and:
Your blood sugar is higher than 240 milligrams per deciliter (mg/dL)
You have an illness such as pneumonia, heart attack, or stroke
Nausea or vomiting occur
You are pregnant
A negative test result is normal.
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
An abnormal result means you have ketones in your urine. The results are usually listed as small, moderate, or large as follows:
Small: <20 mg/dL
Moderate: 30 to 40 mg/dL
Large: >80 mg/dL
This may be due to diabetic ketoacidosis, a problem that occurs in people with Type 1 diabetes. It occurs when the body has no insulin or the insulin does not cause the right signal in fat cells to prevent fat from being broken down to form ketones.
An abnormal result may also be due to:
Abnormal food or nutrition intake due to: anorexia nervosa (an eating disorder), fasting, high protein or low carbohydrate diet, starvation, vomiting over a long period
McPherson RA, Ben-Ezra J. Basic examination of urine. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 28.
Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.