What is a serum ketones test?
A serum ketones test determines the levels of ketones in
your blood. Ketones are a byproduct produced when your body uses only fat,
instead of glucose, for energy. Ketones aren’t harmful in small amounts.
When ketones accumulate in the blood, the body enters ketosis. For some
people, ketosis is normal. Low-carbohydrate diets can induce this state. This
is sometimes called nutritional ketosis.
If you have type 1 diabetes, you may be at risk for diabetic ketoacidosis
(DKA), which is a life-threatening complication in which your blood becomes too
acidic. It can lead to a diabetic coma or death.
Contact your doctor immediately if you have diabetes and
have a moderate or high reading for ketones. Some newer blood glucose meters
will test blood ketone levels. Otherwise, you can use urine ketone strips to measure
your urine ketone level. DKA can develop within 24 hours and can lead to
life-threatening conditions if left untreated.
Although it’s rare, people with type 2 diabetes do develop DKA, according to
Forecast. Some people may also have alcoholic ketoacidosis from long-term
alcohol abuse or starvation ketoacidosis from fasting too long.
Call your doctor immediately if your blood sugar levels are high, your
ketone levels are moderate or high, or if you’re feeling:
- pain in the abdomen
- nauseated or you’re vomiting for over 4 hours
- sick with a cold or the flu
- excessive thirst and symptoms of dehydration
- flushed, especially on your skin
- shortness of breath, or breathing rapidly
You may also have a fruity or metallic scent on your
breath, and a
blood sugar level more than 240 milligrams per deciliter (mg/dL). All of
these symptoms can be warning symptoms of DKA, especially if you have type 1
What are the risks
of a serum ketone test?
The only complications that come from a serum ketone test come from taking a
blood sample. The healthcare provider may have difficulty finding a good vein
from which to take the blood sample, and you may have a slight prick sensation
or bruising at the site of the needle insertion. These symptoms are temporary
and will resolve on their own after the test, or within a few days.
Purpose of the serum ketone test
Doctors use serum ketone tests primarily for screening DKA, but
they may order them to diagnose alcoholic ketoacidosis or starvation as well. Pregnant
women with diabetes will often take the urine ketone test if their meters aren’t
able to read blood ketone levels to track ketones frequently.
The serum ketone test, also known as the blood ketone test, looks at how much
ketone is in your blood at the time. Your doctor can test for the three known
ketone bodies separately. They include:
The results aren’t interchangeable. They can help diagnose different
Beta-hydroxybutyrate indicates DKA and accounts for 75 percent of ketones.
High levels of acetone indicate acetone poisoning from alcohol, paints, and
nail polish remover.
You should test for ketones if you:
- have symptoms of ketoacidosis, such as excessive
thirst, fatigue, and fruity breath
- are sick or have an infection
- have blood sugar levels above 240 mg/dL
- drink a lot of alcohol and eat minimally
How is the serum ketone test done?
A serum ketone test is done in a laboratory setting using a sample of your blood.
Your doctor will tell you if you need to prepare and how to prepare if you do.
A healthcare provider will use a long, thin needle to draw several small
vials of blood from your arm. They’ll send the samples to a lab for testing.
After the blood draw, your doctor will place a bandage over the injection
site. This can be taken off after an hour. The spot may feel tender or sore
afterward, but this typically goes away by the end of the day.
Home kits for testing ketones in the blood are available. You should use
clean, washed hands before drawing blood. When you place your blood on the
strip, the monitor will display the results about 20 to 30 seconds later. Otherwise,
you can monitor for ketones using urine ketone strips.
What do your results mean?
When your test results are available, your doctor will review them with you.
This may be over the phone or at a follow-up appointment.
High levels of ketones in the blood can indicate:
- uncontrolled serum glucose levels
- alcoholic ketoacidosis
You can still have ketones even if you don’t have diabetes. The presence of
ketones tends to be higher in people:
- on a low-carbohydrate diet
- who have an eating disorder or are in treatment
- who are constantly vomiting
- who are alcoholics
You may want to consider them with your blood sugar level. A normal blood
sugar level for someone without diabetes is 70-100 mg/dL before eating and up
to 140 mg/dL two hours after.
What to do if your results are positive
Drinking more water and sugar-free fluids and not exercising
are things you can do immediately if your tests return high. You may also need
to call your doctor for more insulin.
Go to the ER immediately if you have moderate or large
amounts of ketones in either your blood or urine. This indicates that you have ketoacidosis,
and it can lead to a coma or have other life-threatening consequences.