Blood glucose (sugar) is the amount of sugar in your blood at a given time.

It is important to check your blood sugar levels, because it will:

  • Provide a quick measurement of your blood sugar level at a given time;
  • Determine if you have a high or low blood sugar level at a given time;
  • Show you how your lifestyle and medication affect your blood sugar levels; and
  • Help you and your diabetes health-care team to make lifestyle and medication changes that will improve your blood sugar levels.

How often should you check your blood sugar levels?

How frequently you check your blood sugar levels should be decided according to your own treatment plan. You and your health-care provider can discuss when and how often you should check your blood sugar levels. Checking your blood sugar levels is also called Self-Monitoring of Blood Glucose (SMBG).

How do you test your blood sugar levels?

A blood glucose meter is used to check your blood sugar at home. You can get these meters at most pharmacies or from your diabetes educator. Talk with your diabetes educator or pharmacist about which one is right for you. Once you receive a meter, ensure you receive the proper training before you begin to use it.

Ask your health-care provider about:

  • How and where to draw blood
  • How to use and dispose of lancets (the device that punctures your skin)
  • The size of the drop of blood needed
  • The type of blood glucose strips to use
  • How to clean the meter
  • How to check if the meter is accurate
  • How to code your meter (if needed)

A flash glucose meter (FGM) is a new generation device that uses sensor scans for blood sugar monitoring and doesn’t require finger pricks.

A continuous glucose monitor (CGM) is a device that checks blood sugar level using a sensor inserted under your skin.

How do you keep your blood sugar levels within their target range?

If you have diabetes, you should try to keep your blood sugar as close to target range as possible. This will help to delay or prevent complications of diabetes. Maintaining healthy eating habits and an active lifestyle, and taking medication, if necessary, will help you keep your blood sugar levels within their target range. Target ranges for blood sugar can vary. It depends on a person’s age, medical condition and other risk factors.

Targets for pregnant women, older adults and children 12 years of age and under are different. Ask your health-care provider what your levels should be.

Recommended blood sugar targets for most people with diabetes*

(Your target may not be the same as the examples in this blood sugar levels chart. Yours should be specific to you.)

A1C** Fasting blood glucose (sugar)/ blood sugar before meals (mmol/L) Blood sugar two hours after eating (mmol/L)
Target for most people with diabetes 7.0% or less 4.0 to 7.0 5.0 to 10.0 (5.0 – 8.0 if A1C** targets not being met)

* This information is based on the Diabetes Canada 2018 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada and is a guide.
** A1C is a measurement of your average blood sugar control for the last two to three months and approximately 50 per cent of the value comes from the last 30 days.

Talk to your health-care provider about YOUR blood sugar target ranges

You should have your A1C measured every three months, when your blood sugar targets are not being met or when you are making changes to your diabetes management.

A1C, before meal and after meal blood sugar levels are all important measurements of your diabetes control.

Managing your blood sugar when you’re ill

When you are sick, your blood sugar levels may fluctuate and be unpredictable. During these times, it is a good idea to check your blood sugar levels more often than usual (for example, every two to four hours). It is also very important that you continue to take your diabetes medication. If you have a cold or flu and are considering using a cold remedy or cough syrup, ask your pharmacist to help you make a good choice. Many cold remedies and cough syrups contain sugar, so try to pick sugar-free products.

When you are sick, it is VERY IMPORTANT that you:

  • Drink plenty of extra sugar-free fluids or water; try to avoid coffee, tea and colas, as they contain caffeine, which may cause you to lose more fluids;
  • Replace solid food with fluids that contain sugar if you can’t eat according to your usual meal plan;
  • Try to consume 15 grams of carbohydrate every hour if you are not able to follow your usual meal plan;
  • Call your doctor or go to an emergency room if you vomit and/or have had diarrhea two times or more in four hours; and,
  • If you are on insulin, be sure to continue taking it while you are sick. Check with your health-care team about guidelines for insulin adjustment or medication changes during an illness.

For more information, learn about low and high blood sugar levels.

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