A ketone test
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.
Ketones can be tested in a laboratory. Or you can test for ketones anywhere you may be by using home blood or urine tests.
Why It Is Done
A blood test analyzed by a laboratory 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
Home blood or urine ketone tests:
- Monitor a person who has diabetes, especially when that person is sick.
- Monitor a person on a low-carbohydrate
diet and/or high-fat diet.
- Monitor a person who is not able to eat due to anorexia or fasting, who is vomiting a lot, and/or who has diarrhea.
- Monitor a person who is sick.
- Monitor a pregnant woman who has diabetes or has developed
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
Blood test by a laboratory
The health professional taking a sample
of your blood will:
- Wrap an elastic band around your upper arm to
stop the flow of blood. This makes the veins below the band larger so it is
easier to put a needle into the vein.
- Clean the needle site with
- Put the needle into the vein. More than one needle stick
may be needed.
- Attach a tube to the needle to fill it with
- Remove the band from your arm when enough blood is
- Apply a gauze pad or cotton ball over the needle site as
the needle is removed.
- Apply pressure to the site and then a
Blood test at home
Some home blood sugar meters can also measure blood ketones. You use the same finger-prick method that you use to measure blood sugar.
- Collect a urine sample in a clean
- Follow the manufacturer's directions on the bottle of
test strips or tablets.
- Avoid getting toilet paper, pubic hair,
stool, menstrual blood, or other foreign matter in the urine sample.