Checking Ketone Levels

What are ketones?

The human body primarily runs on glucose. When your body is low on glucose, or if you have diabetes and don’t have enough insulin to help your 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. However, people with diabetes are at risk for ketone buildup in their blood. If left untreated, people with type 1 diabetes are at risk for developing a condition called diabetic ketoacidosis (DKA). While more rare, it’s possible for people with type 2 diabetes to experience DKA in certain circumstances as well.



What are the symptoms of ketone buildup?

If you have diabetes, you need to be especially aware of the symptoms that having too many ketones in your body can cause. These include:

  • a dry mouth
  • blood sugar levels greater than 240 milligrams per deciliter (mg/dL)
  • strong thirst
  • frequent urination

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

  • confusion
  • extreme fatigue
  • flushed skin
  • a fruity breath odor
  • nausea
  • vomiting
  • stomach pain
  • trouble breathing

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


Testing and results

How are ketones tested?

You can use blood or urine tests to measure your ketone levels. At-home testing kits are available for both types of tests, although urine testing continues to be more common. Urine tests are available without a prescription at most drugstores, or you can buy them online.

You should test your 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

To perform a urine test, you will urinate into a clean container and dip the test strip into the urine. If a child 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 special 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. When you have ketones present in your urine it’s 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’ll prick your finger with a needle and place a small drop of blood onto the testing area.

Doctors often recommend that people who’ve just been diagnosed with diabetes test their ketones twice daily.

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

  • normal/negative: less than 0.6 millimoles per liter (mmol/L)
  • low to moderate: between 0.6 to 1.5 mmol/L
  • high: 1.6 to 3.0 mmol/L
  • very high: greater 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.



What happens if your ketone levels get too high?

Ketones can make your blood acidic. Acidic blood can cause a serious condition known as diabetic ketoacidosis (DKA).

If you don’t get treatment for high ketone levels, DKA can occur. The most serious effects of DKA include:

  • swelling in the brain
  • a loss of consciousness
  • diabetic coma
  • death

This is why it’s important to have a plan of action in the event that your ketone levels become too high.



Treatment for high ketone levels

Treating high ketone levels immediately can 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 will 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, the 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.


In an emergency situation, people are usually given insulin through an IV to improve their ability to use excess glucose in the blood for energy. This usually 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 you would 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. In these cases, your doctor may prescribe treatments for the underlying illness as well.



Are there ways to prevent high ketone levels?

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

Check blood sugar levels regularly

Your doctor will recommend how frequently you should check your blood sugar levels, but this is typically four to six times per day. You should check your blood sugar more often if:

  • your blood sugar levels are getting higher
  • you’re having symptoms of high or low blood sugar
  • you’re sick

Follow a healthy diet plan

Managing your carbohydrate intake and insulin dosage is vital for managing diabetes. Be sure to talk to your 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 can refer to it as needed.

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. You should talk to your doctor if you’re concerned about your ketone levels being frequently high.

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