Low carb

How to test at home

How to test at home

Blood ketone meters are devices that allow you to test the ketones circulating in your body. These are chemicals produced by the liver when the body needs to burn fat for fuel.

Everyone has ketones, and they are not normally a health concern. But if you have diabetes, high levels of ketones can cause diabetic ketoacidosis (DKA), a life-threatening complication.

Monitoring your ketone levels with a blood ketone meter may be recommended, especially if you have type 1 diabetes. Ketone testing is especially important during times of illness.

You can also use a blood ketone meter if you’re on a ketogenic diet and want to make sure you’re in ketosis.

This article discusses the purpose of blood ketone testing and the various blood ketone meters available. It also explains the use of blood ketone test strips and tips for buying them.

Blood ketone meters for home testing

To test for ketones in your blood, you will need a blood ketone meter and a kit that includes the lancet pen and ketone test strips. These readers also read blood glucose test strips. Download results to your computer.

Other makes and models may be available, including but not limited to:

  • Extra precision: This meter from Abbott Diabetes Care can store up to 450 readings and will display your blood glucose averages over different time periods. You must enter a code to switch from glucose test to ketone test. Users seem to be more satisfied with the Precision brand, and researchers find it more accurate. The strips require 1.5 microliters of blood. It also has a backlit screen.
  • NovaMax Plus: This reader from Nova Biomedical is often provided free with the purchase of two boxes of test strips. You do not need to enter a code to switch between blood glucose and ketone testing; it does this automatically when you insert a ketone test strip. If you use it primarily for blood sugar, it will remind you to test for ketones if your blood sugar is 250 mg/dL or higher. Test strips for the Nova Max are less expensive but also more fragile and give more error messages, requiring retesting. The strips require less blood than Precision strips, only 0.3 microliters.

Ketone test strips

You need to buy ketone test strips because glucose test strips do not test for ketones. You will also need to use blood from your fingertip rather than blood from another site.

The strips are for single use only. They can be the expensive part of testing, especially if they’re not covered by your insurance.

Follow these tips and precautions when buying test strips:

  • Make sure you get the correct test strips for the correct meter (they are not interchangeable).
  • Pay attention to the expiration dates on the strips, both when you receive your purchase and when testing your blood. Expired strips will not give accurate results.
  • The Food and Drug Administration (FDA) warns against buying used test strips. Although it may be legal, you risk getting a product that has not been properly stored and could be expired.
  • The FDA also warns against purchasing tapes that have not been cleared by the agency for sale in the United States.

How to test your blood for ketones

Artwork by Seth Williams. © Fine, 2017.
  1. Load a needle into the lancet pen according to the instructions on the package.
  2. Wash your hands with soap and dry them well.
  3. Remove a test strip from the package and insert it into the meter.
  4. Place the lancet pen on the side of your finger and press the button.
  5. Gently squeeze your finger to get a drop of blood. You will need a large drop to properly load the tape. After doing this two or three times, you will have an idea of ​​how much blood you need. With the precision meter, you need a larger drop of blood than when testing blood glucose (even using the same meter).
  6. Touch the end of the test strip with the drop of blood until it fills the small opening and the meter registers.
  7. Wait for the meter to give you a reading (just a few seconds).
  8. Save your results. Discard the test strip.

Ketone test in diabetes

People with diabetes test ketones to look for signs of diabetic ketoacidosis. If you have diabetes, you should test for ketones when:

  • Your blood sugar is persistently above 240 mg/dl, especially if you have symptoms of DKA. Most diabetics frequently have blood sugar >240 mg/dL.
  • You feel bad.
  • You have signs of dehydration.
  • Your blood sugar has risen too much overnight.

Studies have shown that monitoring blood ketones is effective in reducing emergency room visits and hospitalizations. It also improves recovery time in people who develop diabetic ketoacidosis.

Blood Ketone Results for People with Diabetes

Learn how to read your blood ketone results and discuss with your healthcare provider which level you should call them to, which will depend on individual factors. Here are the general guidelines:

  • A level of 0.6 mmol/L up to 1.0 mmol/L is considered normal for most people with diabetes.
  • A level between 1.0 and 1.5 mmol/L is generally considered the point at which you call your health care provider.
  • A level between 1.5 and 2.9 mmol/L indicates a risk of ketoacidosis. You should call your health care provider immediately.
  • A level above 3.0 mmol/L is a medical emergency. You should go to the emergency room or call 911.

Ketone test for ketogenic diets

If you have normal blood sugar levels, your blood ketones may be highest in the morning after your overnight fast. However, many people report that their ketones increase throughout the day. If you want to track your blood ketones day by day, picking a time of day and sticking to it will give you the best comparison.

Some factors other than overall diet that can cause fluctuations include exercise and the consumption of fats that contain medium-chain triglycerides, such as coconut oil or MCT oil. And, of course, eating something (usually high in carbs) that knocks you out of ketosis will cause your ketone level to drop.

How to Interpret Ketogenic Diet Results

If you’re new to ketogenic diets and have a nutritional ketosis goal (often defined as between 0.5 and 3 mmol/L), be aware that it can take two to four weeks to consistently hit that range. It often takes a lot of tweaking to figure out what you can and can’t eat, even for low-carb veterans.

The ketone meter was developed to alert people with insulin-dependent diabetes to the signs of dangerous diabetic ketoacidosis. However, if you are non-diabetic and follow a ketogenic diet, you are using it for an entirely different reason. In this case, elevated ketones are not a sign of high blood sugar, are not caused by protein breakdown, and are not toxic.

For detailed information on nutritional ketosis, check out the books by Jeff Volek and Stephen Phinney: The Art and Science of Low Carb Living and The Art and Science of Low Carb Performance.

Ketoacidosis vs Ketosis

Ketoacidosis occurs when blood sugar and ketone body levels are high. This increases the acidity of the blood and is a medical emergency.

Ketosis, on the other hand, just means you have high ketones, but not so high that they are dangerous. It can happen overnight or when you are on a diet.

A word from Verywell

If you have diabetes, measuring your blood ketone levels can reduce your risk of hospitalization and diabetes complications such as ketoacidosis. Discuss home ketone testing with your healthcare provider. If you are not diabetic, you may be unfamiliar with using fingertip home blood testing and will need to learn how to do it correctly.

When purchasing an FDA approved ketone meter, it is an individual choice and what you find easiest to use. Always follow the instructions carefully and repeat the test if you think you have made a mistake, as this will affect the results.

Frequently Asked Questions

  • Are blood ketone meters more accurate than urine test strips?

    Yes. Additionally, research indicates that people find blood ketone meters more convenient and are more likely to test for ketones with one than with urine ketone strips.

  • Does insurance cover blood ketone meters?

    Maybe, but only if the ketone reader is medically necessary. Insurance is unlikely to cover blood ketone meters for people testing to see if they are in dietary ketosis. However, people with diabetes who have a history of ketoacidosis may be able to argue for coverage.

  • What should my blood ketone levels be in ketosis?

    When using a blood ketone meter to monitor your ketone levels on the keto diet, nutritional ketosis is between 0.5 and 3 mmol/L. You are in ketosis if your ketone meter results fall within this range.

  • Does Drinking Water Reduce Ketones?

    Yes, drinking water can help flush ketones from your body. For people with diabetes, it can help prevent diabetic ketoacidosis (DKA). For those following a keto diet for weight loss, it may help minimize diet-related side effects, such as bad breath.

  • How long can you safely stay in ketosis?

    It’s unclear how long you can safely stay in ketosis. A 2021 study found that following a ketogenic diet for long periods of time can lead to negative health consequences, including increased bad cholesterol and risk of chronic kidney disease, cardiovascular disease, and more.