Testing your blood sugar

David Kinshuck


Glucose sensors

Sensors are highly recommended for all people with type 1 diabetes: Freestyle or Dexcom.

This author also recommends them for peope with type 2 diabetes using multiple insulin injections (fbut peole with type 2 diabetes would have to pay privately for them)

"CGM may be considered appropriate under the following situations:

CGM use can be applied if the following factors also apply: [170]

Sensor can adjust insulin dose, as can new pumps. ('Closed Loop').

Using such a system the sensor will control the an insulin pump, stopping it injecting insulin if the glucose levels are dropping quickly, increasing it if they go up. But you still have to tell the pump how many CP (carbohydrate portions) you eat at mealtimes. 


Buying a glucose testing meter

There are many new glucose testing meters. Your diabetes nurse will need to show you how to use these. For people with no fingers or very tender fingers there is a 'vaculance' which can be used on other parts of your body, including your tummy. Please ask your specialist nurse to advise you, especially if you have difficulties as poor sight or no fingers. See lancets.


Using a glucose testing meter

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Prick the side of the finger


To test your sugar/glucose level, follow the instructions with your meter:

  1. Wash your hands with warm soapy water, dry them, otherwise you may measure the sugar content of your last meal!
  2. warm and shake your hands, particularly if your finger does not bleed much when pricked. This increases the blood flow so you bleed more when you prick, making it easier to obtain blood to test
  3. Prepare the blood sugar meter (glucose meter). Follow the instructions included with your meter.
  4. Place a strip in the meter (put the lid back on the strip bottle immediately)
  5. this excellent page tells you how to test in detail, with an extract below
  6. Insert a clean lancet in the lancet device.
  7. Adjust the lancet prick depth... how deeply the lancet goes into the skin.
  8. Prick the side of your fingertip with the lancet.
  9. Do not stick the tip of your finger; the prick will be more painful and you may not get enough blood to do the test accurately.
  10. (Some new blood sugar meters use lancet devices that can obtain a blood sample from sites other than the fingers, such as the palm of the hand or the forearm).
  11. Put a drop of blood on the correct spot of the test strip. Some meters also allow you to put the test strip in the machine before placing the drop of blood on it.
  12. Press on the your finger prick site
  13. Follow the directions with your blood sugar meter to get the results.
  14. Write down the results and the time that you tested your blood..also record food/exercise/how you feel.
  15. adjust the lancet depth for next time..if there was more blood than you needed, use less depth next time. If there was not enough, use a deeper depth next time.


Use the results

There is little point in testing your sugar if you do not use the results. See HBA1c & type 2 diabetes.htm and type 2 diabetes for suggestions as to what to do. In principle aim for these levels:


Units mmols/l type 1 children & young people type 1 adults >type 2 adults
aim for a sugar before meals 4-8 4-7 4-7
aim for 2 hours after meals less than 10 less than 9 less than 9


Type 2 diet well controlled..HbA1c below 6.5% /  48mmol/

If you have type 2 diet controlled diabetes you do not need to test often. This article ( & BMJ 2012) suggests there is no point testing regularly if your diabetes is well controlled.

I would suggest occasional testing, perhaps once a week, at different times as below, is probably best, just to check your diabetes is controlled.

But if your results are higher than ideal, you do need to take action


Type 2 on diet, not well controlled..HbA1c above 6.5% / 48mmol/mol

If your diabetes is not perfectly controlled and you are trying to improve your control, you should test:

Type 2 diabetes using tablets, but not on insulin

Good times to test glucose for non-insulin users (different times each day)

Aim for

What do results mean?

Higher results for 2-3 days means you need more medication/less food/more exercise .

Lower results for 2-3 days means you may need less gliclazide etc (metformin does not cause hypos

On insulin, type 1 or type 2 diabetes

To achieve good control insulin pumpers test their sugar 7 times a day: http://www.insulin-pumpers.org/about.shtml#bgtest .    See type 1 diabetes/type 2 & insulin.