Ketones — The 6 Must-Knows


1 – What are ketones?

Ketones are chemicals that build up when your body starts to burn fat for energy. The most common cause of ketones in people with diabetes is insulin deficiency. Without enough insulin, glucose builds up in the blood stream and can’t enter cells. The cells then burn fat instead of glucose. This results in ketones forming in the blood and eventually spilling into urine.

2 – Why can ketones be dangerous?

Having ketones can indicate that your body needs more insulin. (Always monitor your blood sugar levels to know how much insulin you need.) If you have a build up of ketones, this can lead to diabetic ketoacidosis (DKA). Signs of DKA include moderate or large ketones, nausea, vomiting, abdominal pain, fruity, or acetone (think nail polish remover) breath, rapid breathing, flushed skin and lack of energy. If left untreated, it can lead to a serious and life-threatening diabetic coma or death. High levels of ketones are toxic to the body and if you’re experiencing these, you should seek out medical attention.

3 – When and how should you check for ketones? 

You should be checked anytime your blood sugar is above 13.3 mmol/L240 mg/dl or any time you are sick. This includes any minor illness such as a cold.

There are a few different ways to check for ketones, and there are positives and negatives for each method. The most reliable way of checking for ketones is by using blood ketone meters, which measure BHB (the primary ketone found when in DKA). The actual way that one uses a ketone meter is exactly like a blood glucose meter, since you are using a blood sample. These meters required typically cost between $30 and $60, and the test strips are upwards of $1 each. You can find these meters at Walmart or Amazon.

You can also use breath ketone meters to measure acetone, a type of ketone that is found in breath. This method is convenient and only requires a one time purchase of a breath ketone meter. However, these meters are expensive, and can cost around $200. This might be economical if you are expecting to be regularly checking for ketones.

Another, less reliable, way to check for ketones is by using ketone strips, which use a urine sample to measure a particular ketone released through urine. These strips are very cheap, and cost about a quarter each. However, they are not as accurate as a blood ketone meter because it takes longer for ketones to reach urine and hydration can also affect results. You can find ketone strips at drug stores.

4 – Can you get ketones with a high blood sugar?

Ketones typically accompany high blood sugar. They indicate that your body needs more insulin. Most often if your body needs more insulin, it means you probably have a high blood sugar. Also, when an illness is present, your body releases hormones in response to the stress. These hormones lead to elevated blood glucose. That is why it’s recommended to test ketone levels during illness. 

5 – Can you get ketones with a normal or low blood sugar?

Ketones can also be present when your blood sugar is normal or low. These are sometimes referred to as “starvation ketones” or “nutritional ketones.” During an illness or extreme diet change, if you have a significant decrease in carb intake, this can lead to the body using fat for energy because there are not enough carbs present to burn. Your blood sugar could remain normal or even be low in this case but your body could still be producing ketones. 

6 – What should you do if you have ketones?

It is recommended that you drink 8 ounces of water or carb/caffeine free beverage every 30-60 minutes to help flush out the ketones. Again, ketones are a sign that your body needs more insulin. Some people might already have an insulin dosing plan in place related to ketones. It’s typically a percentage of your daily long-acting dose or percentage of your total daily basal volume (for pump users) based on whether ketones are small, moderate, or large. It is always best to call your endocrinologist to verify what they recommend when ketones are present.    

This piece is part of Beyond Type 1’s resources on DKA + managing ketones—find the complete collection of resources here.

WRITTEN BY Kyla Schmieg, BSN, RN, POSTED 04/12/16, UPDATED 12/21/22

Kyla Schmieg, BSN, RN, currently works as a pediatric endocrinology RN in Cincinnati, Ohio, working on the same unit she was diagnosed at 26 years ago. She was diagnosed with type 1 in 1990. She loves that her job allows her to work with newly diagnosed type 1 kids and families. She loves educating people about diabetes; it’s the main reason she became a nurse! She also believes it’s important to put out there that although type 1 needs to be taken seriously, it is not something that should impact or limit your dreams or ambitions.