Also Known As
Serum or Plasma ketones
Ketone bodies
Beta-hydroxybutyric acid
Acetoacetic acid
Formal Name
Blood Ketones
This article was last reviewed on
This article waslast modified on 22 February 2022.
At a Glance
Why Get Tested?

To determine whether excessive ketones are present in the blood, to detect diabetic ketoacidosis (DKA), to detect alcoholic ketoacidosis and to monitor ketogenic diet therapy used in the treatment of epilepsy.

When To Get Tested?

When you have symptoms associated with ketoacidosis or being monitored on a ketogenic diet.

Sample Required?

A blood sample taken from a vein in your arm or a drop of blood from your finger.

Test Preparation Needed?

No test preparation is needed.

On average it takes 7 working days for the blood test results to come back from the hospital, depending on the exact tests requested. Some specialist test results may take longer, if samples have to be sent to a reference (specialist) laboratory. The X-ray & scan results may take longer. If you are registered to use the online services of your local practice, you may be able to access your results online. Your GP practice will be able to provide specific details.

If the doctor wants to see you about the result(s), you will be offered an appointment. If you are concerned about your test results, you will need to arrange an appointment with your doctor so that all relevant information including age, ethnicity, health history, signs and symptoms, laboratory and other procedures (radiology, endoscopy, etc.), can be considered.

Lab Tests Online-UK is an educational website designed to provide patients and carers with information on laboratory tests used in medical care. We are not a laboratory and are unable to comment on an individual's health and treatment.

Reference ranges are dependent on many factors, including patient age, sex, sample population, and test method, and numeric test results can have different meanings in different laboratories.

For these reasons, you will not find reference ranges for the majority of tests described on this web site. The lab report containing your test results should include the relevant reference range for your test(s). Please consult your doctor or the laboratory that performed the test(s) to obtain the reference range if you do not have the lab report.

For more information on reference ranges, please read Reference Ranges and What They Mean.

What is being tested?

This test measures the amount of ketones in the blood. Ketones are produced during the break down of fats. They are made when glucose is not available as an energy source. When fatty acids are metabolised, ketones build up in the blood, causing first ketosis, and then ketoacidosis, a form of metabolic acidosis. This condition is most frequently seen with uncontrolled type 1 diabetes and can be a medical emergency.

There are three ketones or ketone bodies, acetoacetate, acetone, and beta-hydroxybutyrate, a reduced form of acetoacetate. Beta-hydroxybutyrate is the main ketone present in severe diabetic ketoacidosis (DKA). Ketone tests measure one or more ketone bodies and therefore test results may differ.

Blood testing gives a snapshot of the amount of ketones that have accumulated at the time that the sample was collected. Urine ketone testing shows recent rather than current blood ketones. Urine testing is much more commonly used than that for blood ketones. It may be performed by itself, with a urine glucose test, or as part of a a range of tests in urine called urinalysis. The urine methods measure either acetoacetate or both acetoacetate and acetone but they do not detect the other ketone beta-hydroxybutyrate.

Blood ketones can be measured in a laboratory or with a handheld monitor. The laboratory test uses serum or plasma, the liquid portion of the blood after the cells have been removed, to measure acetoacetate and/or beta-hydroxybutyrate. When whole blood from a fingerprick is tested for ketones using a handheld monitor, the monitor measures beta-hydroxybutyrate. This test may sometimes be done at a person’s bedside in a hospital and with the appropriate test device by a person at home.

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Common Questions
  • How is it used?

    Blood ketones are mainly used to screen for, detect, and monitor diabetic ketoacidosis (DKA) in people with type 1 and sometimes type 2 diabetes. DKA can occur when blood sugar is markedly increased, often due to illness, severe infection, pregnancy.

    Diabetic ketoacidosis (DKA) is seen with rapidly increasing blood glucose, a severe lack of insulin, and a disruption of acid-base balance. Excess ketones and glucose are passed into the urine by the kidneys to flush them from the body. This causes increased urination, thirst, dehydration, and a loss of electrolytes. The affected person may also experience symptoms such as rapid breathing, shortness of breath, a fruit-scent to the breath (the smell of some of the ketones), feeling sick, vomiting, tiredness, confusion, and eventually coma. Ketosis and ketoacidosis may also be seen with starvation, alcoholism, and with high-fat low-carbohydrate diets.

    Blood ketones are sometimes used, with other tests such as blood gases, glucose, and electrolytes to detect ketoacidosis in those who do not have diabetes but have signs and symptoms of diabetic ketoacidosis (DKA) due to, for example, ingestion of excessive amounts of alcohol.

  • When is it requested?

    Blood ketone tests may be used when a person with diabetes has symptoms of DKA and may also be performed whenever there is the potential for DKA to develop, such as when someone with diabetes is sick or pregnant. Some signs and symptoms of ketoacidosis include:

    • increased urination, excessive thirst
    • dehydration, loss of electrolytes
    • rapid breathing, shortness of breath
    • a fruit-scent to the breath
    • nausea, vomiting
    • fatigue
    • confusion
    • sometimes coma

    In someone without diabetes, blood ketones are usually requested when the patient has symptoms of ketosis or ketoacidosis.

  • What does the test result mean?

    If blood ketone concentrations are increased then the person has some degree of ketosis or ketoacidosis. If concentrations are low or normal then the person either does not have excess ketone production or the ketone body that is elevated is not being detected by the test method used.

  • Is there anything else I should know?

    Recent studies have shown that serum ketones and beta-hydroxybutyrate testing are both effective in diagnosing diabetic ketoacidosis. Beta-hydroxybutyrate testing is not available in most laboratories.

  • If I have diabetes can I just test for glucose instead of ketones?

    They are related but not the same thing. While increases in ketones are associated with high glucose concentrations, they can also occur with moderate glucose levels in many conditions, such as when you are sick. People with diabetes often do tests for blood glucose but not for ketones.

  • Can I test for ketones in my urine instead of my blood?

    The urine is tested much more frequently than blood for ketones.

  • Can I get DKA if I have type 2 diabetes?

    Yes, although it is not as common as in type 1 diabetes. It may occur if you have a severe infection or illness.

  • Can I have ketosis or ketoacidosis and not know it?

    You could have some degree of ketosis with few symptoms but the accumulation of ketones will eventually triggers the symptoms.