Ketone Testing

What Are Ketones?

Ketones are produced when the body burns fat for energy or fuel. They are also produced when you lose weight or if there is not enough insulin to help your body use sugar for energy. Without enough insulin, glucose builds up in the blood. Since the body is unable to use glucose for energy, it breaks down fat instead. When this occurs, ketones form in the blood and spill into the urine. These ketones can make you very sick.

How Do You Check for Ketones?

You can see if your body is making any ketones by doing a simple urine or blood test. Talk to your healthcare provider or educator about the best way for you to check for ketones.

Urine Ketone Checking

There are several products available for ketone testing and they can be purchased, without a prescription, at your pharmacy. Common product names include: Ketostix, Keto Diastix, and Chemstrip K.

The test result can be negative, or show trace, small, moderate or large amounts of ketones.

Blood Ketone Checking

Two meters are currently available that check blood ketones in addition to blood glucose:

• Precision Xtra blood glucose and ketone meter made by Abbott Diabetes Care
• Nova Max Plus made by Nova Biomedical

Below are the possible results and what they mean:

Below 0.6 mmol/L
Readings below 0.6 mmol/l are in the normal range

0.6 to 1.5 mmol/L
Readings between 0.6 and 1.5 mmol/L may indicate the start of a problem that may require medical assistance.

Above 1.5 mmol/L
Readings above 1.5 mmol/L indicate that you are at risk of developing diabetic ketoacidosis (DKA). Call your diabetes team immediately for advice.

When Should I Check for Ketones?

• Anytime your blood glucose is over 250 mg/dl for two tests in a row.
• When you are ill. Often illness, infections, or injuries will cause sudden high blood glucose and this is an especially important time to check for ketones.
• When you are planning to exercise and the blood glucose is over 250 mg/dl.
• If you are pregnant, you should test for ketones each morning before breakfast and any time the blood glucose is over 250 mg/dl.  

If Ketones Are Positive, What Does This Mean?

There are situations when you might have ketones without the blood glucose being too high. It is possible to have ketones when blood glucose levels are within range and you are trying to lose weight.

If your blood glucose levels are not within range and you are testing positive for ketones, it is important to know that untreated high blood glucose with positive ketones can lead to a life-threatening condition called diabetic ketoacidosis (DKA).

What Should I Do if the Ketone Test Is Positive?

Call your diabetes educator or physician, as you may need additional insulin. Drink plenty of water and fluids containing no calories to "wash out" the ketones. Continue testing your blood glucose every 3 - 4 hours, testing for ketones if the blood glucose is over 250 mg/dl. Do not exercise if your blood glucose is over 250 mg/dl and ketones are present.

Although this content is reviewed by Joslin Diabetes Center healthcare professionals, it is not intended to replace the medical advice of your doctor or healthcare provider. Please consult your healthcare provider for advice about a specific medical condition.