The human body primarily runs on glucose.

When your body is low on glucose — a common concern for people with diabetes, who may not have enough insulin to help cells absorb the glucose — your body starts breaking down fats for energy.

Ketones (chemically known as ketone bodies) are byproducts of the breakdown of fatty acids.

The breakdown of fat for fuel and the creation of ketones is a normal process for everyone.

In a person without diabetes, insulin, glucagon, and other hormones prevent ketone levels in the blood from getting too high by collecting a steady and stable stream of useable glucose.

However, people with diabetes are at risk for ketone buildup in their blood.

When the body begins to break down fatty acids into ketones, it enters a metabolic state known as ketosis.

If left untreated, people with type 1 diabetes are at risk for developing a condition called diabetic ketoacidosis (DKA). While rare, it’s possible for people with type 2 diabetes to experience DKA in certain circumstances as well.

Ketosis: Symptoms, signs, and more »

If you have diabetes, you need to be especially aware of the symptoms that can come along with dangerously high ketone levels. These include:

If you don’t get treatment, the symptoms can progress to:

You should always seek immediate medical attention if your ketone levels are high.

Testing your blood or urine to measure your ketone levels is fairly simple and cheap. At-home kits are available for both types of tests, although urine tests are more common. Urine ketone tests are available without a prescription at most drugstores, or you can buy them online.

Some companies also make breathalyzers that test for acetone, one of the ketone byproducts of fatty acid breakdown. Though these machines can be good options for those who struggle with blood and urine testing, they are less accurate and more expensive.

To perform a urine test, you urinate into a clean container and dip the test strip into the urine. For a child who isn’t potty-trained, a parent can usually press the stick to their child’s wet diaper to test for ketones.

Urine testing strips contain chemicals that change colors when they react with ketones. You can interpret the test results by comparing the test strip to the color chart on the package. The excretion of ketones in your urine is called ketonuria.

An at-home meter is available to test for blood ketones. This is performed in a similar way to a finger-stick glucose test. You prick your finger with a needle and place a small drop of blood onto the testing area of a machine capable of analyzing it.

When to test for ketones

People with diabetes should test their urine or blood for ketones when any of the following occurs:

  • Your blood sugar is higher than 240 mg/dL.
  • You have symptoms of DKA.
  • You feel sick or nauseated, regardless of your blood sugar reading.

Your doctor may also recommend regular ketone testing regardless of how you are feeling.

High ketone levels should be detectable at any time of day. But for the most accurate results, research has shown that testing either early in the morning or a few hours after dinner may be your best shot.

While individual testing may vary, in general, results for ketone testing are labeled in the following way:

normal/negativeless than 0.6 millimoles per liter (mmol/L)
low to moderate0.6 to 1.5 mmol/L
high1.6 to 3.0 mmol/L
very highgreater than 3.0 mmol/L

Call your doctor if your ketones are low to moderate, and seek emergency medical attention if your ketone levels are high to very high.

Ketones can make your blood acidic. Acidic blood can cause DKA. The most serious effects of DKA include:

For people whose ketone levels tend to rise above normal, it’s important to have a plan of action in the event that ketone levels become too high.

Learn more about alcoholic ketoacidosis »

Treating high ketone levels can immediately help you avoid hospitalization for DKA.

Work with your doctor to decide what you need to do to help manage moderate ketone levels.

If you’re unable to treat at home or if your levels continue to rise, you’ll need to receive medical treatment. Treatments can include:

Intravenous (IV) fluid replacement

One DKA symptom is increased urination, which can result in fluid loss. Rehydrating with IV fluids can help to dilute the extra glucose in your blood.

Electrolyte replacement

When a person has DKA, their electrolyte levels tend to be low. Examples of electrolytes include potassium, sodium, and chloride. If a person loses too much of these electrolytes, their heart and muscles can’t function as well.

Insulin

In an emergency situation, people are usually given insulin through an IV to improve their body’s ability to process excess glucose in the blood into energy. This typically involves testing glucose levels on an hourly basis.

When your ketones and blood acid level begin to return to normal, IV insulin may no longer be necessary, and your doctor may recommend you resume your normal insulin therapy regimen.

DKA can also be caused by an underlying illness, such as an infection or a severe stomach bug that causes vomiting and loss of fluids. In these cases, your doctor may prescribe treatments for the underlying illness as well.

Careful management of diabetes is the key to preventing high ketone levels. Do the following to keep your blood sugar levels healthy and your body’s ketone production to a minimum:

Check blood sugar levels regularly

Your doctor will recommend an ideal routine for regularly checking your blood sugar levels, but checks should typically be done 4 to 6 times per day. You should check your blood sugar more often in the following cases:

  • Your blood sugar levels are getting higher.
  • You’re having symptoms of high or low blood sugar.
  • You’re sick.

Follow a balanced diet plan

Managing your carbohydrate intake and insulin dosage is vital for managing diabetes. Be sure to talk with a registered dietitian if you need help managing your diet.

Create a plan for moderate ketone levels

Sometimes moderate ketone levels can be treated before they worsen. A doctor can help you create a plan for when your ketone levels get too high, such as administering additional insulin and drinking more water. Have a sick-day plan set so you know what to do ahead of time.

Always keep ketone testing kits available

Keep ketone testing kits with you at home and when you travel so that you have a fast way to check your ketone levels.

Work closely with a diabetes educator and your doctor

Diabetes management takes constant vigilance to ensure your insulin regimen and eating plan is working effectively. The medication and insulin combination that works best varies depending on the person.

Talk with your doctor if you’re concerned about your ketone levels spiking frequently.