Blood Glucose Testing Information

A blood glucose test is carried out using a blood glucose meter, sometimes called a blood glucose monitor.

A blood glucose test tells you how much glucose is in your blood at any given time. A blood glucose test is performed simply and easily by pricking the side of your finger tip with a lancet to form a drop of blood. A test strip is inserted into the blood glucose meter and the strip sips in the blood for the meter to test. The blood glucose meter will then count down and display the result.

Why do a blood glucose test?

You will need to measure your blood glucose to help you and your diabetes team decide how best to manage your diabetes and to assess how well your treatment is working. You will have been advised of ways to keep your blood glucose level as near to normal as possible by managing your food intake, exercising and / or by taking medication.

Blood glucose monitoring provides you with a picture of your blood glucose control and indicates when changes occur. By self-testing regularly, recording your results and reviewing them with your diabetes care team, you will learn to adjust your diabetes management to maintain your blood glucose levels within agreed targets.

When to test

You should discuss the timing and frequency of blood glucose monitoring with your diabetes care team. You need to carry out enough tests to show your overall blood glucose trends so that you and your diabetes care team can see how well your treatment and management are working and where adjustments might be helpful. The times you need to test should be agreed between you and your care team (e.g. before / after meals), and you should keep a note of the results in your glucose testing record diary. You can also use GLUCOFACTS®Deluxe software to help you understand your results.

At times you may need to increase the number of blood glucose tests you take to get more information and give you a better picture of what is going on, e.g. when you are unwell, following medication changes, at times of increased activity or at times of stress. You should perform a blood glucose test before you drive to make sure that your blood glucose levels have not changed unexpectedly, which would make it unsafe to be in control of a vehicle.

Target level

You should agree your target blood glucose levels with your diabetes care team. Discuss realistic targets for various times of the day and activities to ensure that you are safe at all times.

Remember, glucose testing is only of value if you take action to bring your results back into your target range.

Understanding your results

In order to use your blood glucose results to guide management successfully, you need to understand how to interpret them. Here are some points to help you do this:

  • Glucose monitoring systems: different glucose monitoring devices or blood glucose meters use different methods to measure blood glucose levels and may give different results, even if the blood glucose tests have been performed correctly and at the same time. Use only one type of glucose monitoring device to obtain an overall picture of your blood glucose trends.
  • Test and check the results: some people think they can tell what their blood glucose levels are by how they feel, but this is often not the case and you should always test to be sure. If your blood glucose test result does not match the way your feel, retest your blood glucose levels and make sure the test is performed as instructed by the manufacturer of the glucose monitoring device.
  • Timing of blood glucose monitoring: it takes about 2 hours before you can tell the effect that your meal has had on your blood glucose levels. Blood glucose tests carried out immediately after eating will not really provide any useful information.
  • If your blood glucose levels are higher than your agreed target range 2 hours after eating, your carbohydrate servings may have been too large, or your medication dose could have been inadequate for that meal. You should discuss this with your diabetes care team.
  • Blood glucose levels can be lower than normal after exercise and may remain lower than normal for several hours. If your blood glucose increases after exercise, you may need to adjust your medication (discuss this with your diabetes care team).
  • Your results can be affected by illness, hormonal changes (e.g. during the night, menopause, menstrual cycles), stress, changes in medication, changes in dietary intake and reduced levels of physical activity. Discuss changes in your blood glucose levels with your diabetes care team.


The information on this site is intended to provide you with information about Ascensia Diabetes Care’s products and is not a substitute for professional medical advice or treatment for specific medical conditions.  Any questions or concerns you have regarding diabetes or a medical condition should always be discussed with a qualified medical professional.