Diabetes and Blood Glucose Monitoring
Thursday, December 02, 2021

Importance of regularly checking blood glucose levels

Why monitor?

Blood glucose monitoring may be helpful for the day-to-day management of Type 2 diabetes. Some, but not all people will be asked to check their blood glucose levels at home. This is done using a home blood glucose meter (or glucometer). If you are advised to test your blood glucose levels your doctor or nurse will explain what you need to do, and what your blood glucose results should be, how often and the best times to test.

Monitoring blood glucose helps to determine if you are meeting your glucose targets. It is helpful to remember that the numbers are neither good nor bad. They are simply information used to help you learn what is working well and identify areas for improvement in your diabetes management.

What causes blood glucose levels to change?

There are some common factors that can cause your blood glucose levels to change and understanding how different factors can effect your blood glucose levels will also help to guide your decision making and help you improve your diabetes management.


  • Food & Drink - can cause blood glucose levels to spike if it has high sugar or carbohydrate content, or if it is a large portion
  • Medication - forgetting to take medication or certain medications can cause blood glucose to rise or fall
  • Physical Activity – can help improve your blood glucose
  • Emotions (Stress/Anxiety) - can cause levels to rise
  • Illness - can cause blood glucose to rise (speak to your diabetes team about sick day management)
  • Monitoring Technique – can cause blood glucose levels to rise if hands aren’t washed correctly 

Symptoms of high blood sugar Symptoms of low blood sugar

Extreme thirst

The need to urinate often

Blurry vision

Increased hunger

Feeling tired and weak


Frequent infections eg., thrush


Irregular or fast heartbeat






Headache Pallor



Physical factors that can impact blood glucose results

If for any reason you can’t explain a questionable result here are some other factors to consider:

  • Are your Strips in date
  • Is the Battery securely in the meter
  • Is your Meter calibrated
  • Are your Hands washed & dried thoroughly
  • Is your technique correct

What could happen if I don't have my diabetes under control?

If your blood glucose levels are consistently high in the short term it may cause you to feel unwell. Over long periods (years) high blood glucose levels can cause complications including:

  • Heart and blood vessels - Increased risk of heart disease and strokes
  • Eye disease known as - Diabetic retinopathy
  • Kidney disease
  • Foot problems affecting circulation and nerve ending damage (affecting sensation)

The good news is complications of diabetes are preventable by leading a healthy lifestyle, taking regular physical activity, having a weight appropriate for your height, and not smoking. Regular diabetes checkups with your GP/Diabetes team for routine blood tests, blood pressure, foot checks and attending eye screening appointments will help you ensure your diabetes is managed. Routine check-ups ensure early detection and management of complications should they occur.

What should my target blood glucose level be?

Blood glucose is recommended to be between 4-8mmol/l fasting, and less than 10mmol/l 2 hours after a meal but your diabetes team will set appropriate targets for you.

When should I test?

You will be guided by your diabetic/practice nurse on the best times to test your glucose levels.

If you are on oral medication (tablets) for diabetes check:

  • First thing in the morning
  • 2 hours after meals

If you are on insulin for diabetes check:

  • Before each insulin injection
  • Before driving
  • Before, during and after physical activity
  • If feeling symptoms of a hypo (Hypoglycaemia or hypos are when the glucose (also called sugars) in the blood falls to a low level below 4.0 mmol/l whether you feel it or not)

How often to test 

The frequency of recommended testing will depend on your treatment. 

Diabetes Type Treatment Testing Frequency Test strips covered under HSE schemes
Type 2 Diet controlled Not required* 1 box every 6 months
Type 2 Oral medication - Metformin alone or + other 3 times per week 1 box per month
Type 2  Oral medication - Gliclazide alone or + other 1-2 times per day** 2 boxes per month
Type 2 Insulin alone or + oral medications Up to 4 times per day** No limit
Type 2 Planning pregnancy or are pregnant Up to 7 times per day** This is covered for pre-existing Diabetes when pregnant
Type 1 Insulin 4-10 times per day** No limit
Gestational Insulin alone or + oral medications Up to 7 times per day** Not covered for Gestational diabetes (speak to your pharmacy about signing up for the Drug Payment Scheme, this can save you money on prescription medications and approved medical appliances)

*Test more frequently if there has been a change to any of the contributing factors listed above.

**More testing may be required for driving. (For more info on driving and diabetes see https://www.rsa.ie/) - driving guidelines)

A CarePlus Healthcare Advisor can help you determine which treatment you receive for your diabetes.

How to test

  1. Make sure the meter is clean and ready to use.
  2. After removing a test strip, immediately close the test strip container Test strips can be damaged if they are exposed to moisture.
  3. Wash your hands with soap and warm Dry well. Massage your hand to get blood into your finger. Don’t use alcohol because it dries the skin too much.
  4. Use a lancet to prick your Squeezing from the base of the finger, place the strip in the meter. Gently place a small amount of blood onto the test strip. Note: Be sure to check your meter’s manual, as the correct testing procedure varies from one meter to another.
  5. After a few seconds, the reading will Track and record your results. Add notes about anything that might have made the reading out of your target range, such as food, activity, etc.
  6. Properly dispose the lancet and strip in a sharp’s bin,                                                                                                                                                                                      

Meters may differ in use, but it is important to upgrade your meter every 2 years. Call into your local CarePlus Pharmacy to get your FREE OneTouch Verio Blood Glucose Monitor today. For further information on OneTouch monitors visit OneTouchUK or  OneTouch Ireland YouTube Channel
Information from Diabetes Ireland