Ketones in Blood
Reviewed
Also called: Ketone bodies (blood), Serum ketones, Beta-hydroxybutyric acid, Acetoacetate, Nitroprusside test
A ketones in blood test measures the level of ketones in your blood. Ketones are acids that your body makes when it breaks down fat for energy.
Specimen: Blood
Urgent safety information
DKA is a medical emergency that often develops quickly and can lead to a coma and be life-threatening. If you have severe symptoms of ketoacidosis, seek immediate medical help.
Why this test may be ordered
- To check for diabetic ketoacidosis (DKA) in people with diabetes, especially when sick or pregnant
- If you have symptoms of ketoacidosis such as extreme thirst, frequent urination, nausea, abdominal pain, confusion, or fruity-smelling breath
- If you have conditions that increase risk for high ketones, such as eating disorders, starvation, prolonged vomiting or diarrhea, or alcohol use disorder
- If you eat a low-carbohydrate diet and have symptoms
Preparation and collection
You don't need any special preparations for a ketones in blood test.
A health care professional will take a blood sample from a vein in your arm, using a small needle. To check blood ketones at home, you may use a blood glucose meter that also tests for ketones. Ask your provider how you should test for ketones, when you should test, and what to do if your levels are high.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
Understanding results
If a result or symptoms suggest an emergency, get emergency medical help right away.
It's normal to have some blood ketones, but if your levels are very high and you have symptoms, you may have ketoacidosis.
- Normal or negative: A normal or negative test result usually means that your body is not making too many ketones and you don't have ketoacidosis. Limitation: But a normal test result doesn't always rule out diabetic ketoacidosis (DKA). Next step: If you have questions about your results, talk with your provider.
- High or positive: A high or positive test result means you have ketones in your blood. If you have diabetes, you likely have DKA. Limitation: People who eat a low-carbohydrate ketogenic ("keto") diet to lose weight will have blood ketone levels that are higher but are not high enough to be ketoacidosis. Next step: Ketoacidosis from any cause must be treated. Treatment may include going to the hospital.
- A normal test result does not always rule out diabetic ketoacidosis (DKA) because early DKA may involve a type of ketone not measured by standard lab tests.
- People on a low-carbohydrate ketogenic diet may have higher ketone levels (ketosis) that are not high enough to be ketoacidosis, but it is possible to develop ketoacidosis on a keto diet.
- At-home testing may have variability; follow instructions carefully and discuss with your provider.
What to do next
Ketoacidosis from any cause must be treated. Treatment may include going to the hospital. If you have questions about your results, talk with your provider.
- What do my ketone levels mean for my diabetes management?
- How often should I test my ketones, and when is the best time to test?
- What should I do if my ketone levels are high?
- Are there any symptoms I should watch for that might indicate ketoacidosis?
- Is at-home testing for ketones in blood or urine right for me?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.