A ketone test checks for ketones in your blood or urine. Ketones are substances that are made when the body breaks down fat for energy. Normally, your body gets the energy it needs from carbohydrate in your diet. But stored fat is broken down and ketones are made if your diet does not contain enough carbohydrate to supply the body with sugar (glucose) for energy or if your body can't use blood sugar (glucose) properly.
Some home blood sugar meters can also measure ketone levels in the blood. Home urine tests to measure ketones are available.
Why It Is Done
A blood test is the most accurate method of measuring ketones. It is recommended for all people with diabetes whenever symptoms of illness are present, such as nausea, vomiting, or abdominal pain. These symptoms often happen with high blood sugar and may mean you have diabetic ketoacidosis, a potentially life-threatening condition.
A urine test is the most commonly used method of measuring ketones. But it is less accurate than a blood test. A urine test may be done to:
How To Prepare
No special preparation is needed before having this test.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).
How It Is Done
The health professional taking a sample of your blood will:
How It Feels
The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.
There is normally no discomfort involved with collecting a urine sample.
There is very little risk of a problem from having blood drawn from a vein.
There are no risks associated with collecting a urine sample.
A ketone test checks for substances made when the body breaks down fat for energy (ketones).
If either the test strip or the urine changes color when the tablet is dropped into the sample, ketones are present in your urine sample. The test results are read as negative to 1+ to 4+ or small to large.
You may have ketones in your urine if you:
The level of ketones, and not just the presence of ketones, may be important to your doctor as well. Many conditions can change ketone levels. Fasting usually causes only mild increases in the level, but ketone levels in diabetic ketoacidosis are much higher. Your doctor will discuss any significant abnormal results with you in relation to your symptoms and past health.
What Affects the Test
Reasons you may not be able to have the test or why the results may not be helpful include:
What To Think About
Your doctor may recommend you test for ketones if you have diabetes and you have any of the following conditions:
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