Ketones
Test OverviewA 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. 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 DoneA 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
condition. Home blood or urine ketone tests are done to: - 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
gestational diabetes.
How To PrepareNo 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 DoneBlood test by a laboratoryThe 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
alcohol.
- Put the needle into the vein. More than one needle stick
may be needed.
- Attach a tube to the needle to fill it with
blood.
- Remove the band from your arm when enough blood is
collected.
- Apply a gauze pad or cotton ball over the needle site as
the needle is removed.
- Apply pressure to the site and then a
bandage.
Blood test at homeSome home blood sugar meters can also measure blood ketones. You use the same finger-prick method that you use to measure blood sugar. Urine test- Collect a urine sample in a clean
container.
- 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.
How It FeelsBlood test by a laboratoryThe 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. Blood test at homeYour finger may feel sore after pricking it for a drop of blood for the test. Urine testThere is normally no discomfort
involved with collecting a urine sample. RisksBlood test by a laboratoryThere is very little risk of a problem
from having blood drawn from a vein. - You may develop a small bruise at the
puncture site. You can reduce the risk of bruising by keeping pressure on the
site for several minutes after the needle is withdrawn.
- In rare
cases, the vein may become inflamed after the blood sample is taken. This
condition is called phlebitis and is usually treated with a warm compress
applied several times daily.
Blood test at homeThere is very little risk of complications from testing your blood for ketones with a home blood sugar meter. Urine testThere are no risks associated with
collecting a urine sample. ResultsA ketone test checks for substances made
when the body breaks down fat for energy (ketones).
KetonesNormal: | There are no ketones in your blood or
urine. |
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Abnormal: | Ketones are present in your blood or
urine. |
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Blood test at homeHome blood sugar meters that also test for ketones display results on the meter's screen. In people who have diabetes, blood ketones are expected to be lower than 0.6 mmol/L. Urine testKetones are present in the urine if:
- The test strip changes color after dipping it into the urine.
- The urine changes color after placing the test tablet in it.
You usually compare the color of the test strip or urine to a chart to find out if ketones are present. High valuesYou may have ketones if
you: - Have poorly controlled diabetes or
diabetic ketoacidosis.
- Are on a very
low-carbohydrate or high-fat diet.
- Are
starving or have an eating disorder, including disorders that result in poor
nutrition such as
anorexia nervosa or
bulimia, alcoholism, or poisoning from drinking
rubbing alcohol (isopropanol).
- Have not eaten (fasted) for 18 hours
or longer.
- Are pregnant. Some women have low levels of ketones during pregnancy and this does not affect the fetus. But a moderate or high amount of ketones in a
pregnant woman may harm the fetus and may be an indication of gestational
diabetes.
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 TestReasons you may not be able to
have the test or why the results may not be helpful include: - Taking medicines, such as:
- Levodopa, such as Sinemet or Larodopa.
- Valproate,
such as Depakote, Depacon, or Depakene.
- Vitamin C (ascorbic acid),
when taken in large amounts.
- Waiting a long time after collecting the urine to test it.
What To Think AboutYour doctor may recommend you test for ketones if you have
diabetes and you have any of the following conditions: - You have a blood sugar level that stays higher than the level the doctor has set for you, for example, 300 mg/dL (16.7
mmol/L) for two or more readings.
- You are pregnant.
- You are sick or
feeling very stressed.
- You have
symptoms of diabetic ketoacidosis.
ReferencesOther Works Consulted- Chernecky CC, Berger BJ (2013). Laboratory Tests and Diagnostic Procedures, 6th ed. St. Louis: Saunders.
- Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
CreditsByHealthwise Staff Primary Medical ReviewerE. Gregory Thompson, MD - Internal Medicine Adam Husney, MD - Family Medicine Kathleen Romito, MD - Family Medicine Specialist Medical ReviewerMatthew I. Kim, MD - Endocrinology David C.W. Lau, MD, PhD, FRCPC - Endocrinology Current as ofMarch 13, 2017 Current as of:
March 13, 2017 Last modified on: 8 September 2017
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