Blood Glucose Monitoring
Self-monitoring your blood glucose levels (BGLs) is an important part of managing diabetes because keeping your BGLs in target range helps lower your risk of diabetes-related complications. One of the most important, and often frustrating, factors in managing diabetes is understanding what makes your BGLs go up and down. Food, exercise, stress, medications and illness are just some of the things that can have an impact, which is why self-monitoring is so useful. It gives you the opportunity to check in with your body to see how you respond to different things. For example, has eating a certain food type made your BGL rise, or has a new medication made your BGL drop? Understanding this can then help you make decisions around:
- Food (types and quantities)
- Physical activity (before, during and 24-28 hours after exercise)
- Medications especially when you start or change a medication
- Sick day management
- Driving (Road and Maritime Service recommend a blood glucose level above 5 to drive)
Choosing a blood glucose monitor
There are lots of monitors on the market and it’s important to ensure the one you choose suits your needs. There are monitors that can talk to you, monitors that are small enough to put in your pocket, and monitors that can give you ketone readings as well as blood glucose readings. While you can be confident today’s monitors all meet stringent safety regulations, it is also recommended to talk with your diabetes educator or pharmacist to find the right one for you. They can provide you with additional information, further instruction and support.
When you get a new monitor take the time to read through the manual. This will tell you how to change the time and date (for daylight saving, travel), troubleshoot problems, and the correct testing technique (eg how to insert the test strip).
How to perform a blood glucose check
- Wash your hands in warm soapy water and dry well
- Get your meter, strips, tissue and sharps container
- Insert test strip in your meter
- Prick your finger
- Transfer the blood to the test strip
- Repeat if an error warning, or not enough blood for the reading
- Dispose of lancets in the sharps container
Record your readings in a diary. Many monitors automatically record results, but if you are heading to a doctor’s appointment you may find it useful to write down a coupe of weeks readings in advance to discuss at your appointment.
When should you check your blood glucose level?
When and how often you should test your blood glucose levels depends on each individual, the type of diabetes you have and the tablets and/or insulin being used. Your GP or Credentialled Diabetes Educator will help you decide how many tests are needed and the levels to aim for. Possible times to test are:
- Before breakfast (fasting)
- Before lunch/dinner
- Two hours after a meal
- Before bed
- Before rigorous exercise
- When you are feeling unwell
Tip 1: It is best to prick your fingers on the side rather than the pad because you have fewer nerve endings there and it will hurt less. It also helps lessen scar tissue.
Tip 2: It is recommended to change your lancet every time you prick your finger because using a dull or blunt needle tears at the skin instead of making a clean hole; this can cause pain and discomfort and eventually lead to callous formation (thick, rough hard skin) and black spots (bleeding/bruising). Try and get into the habit of changing your lancet daily at a minimum.
Tip 3: Try not to inject the lancet too deep into your finger. Set the depth between two and four on your lancet device. If the needle goes too deep it can cause damage and black spots (bleeding) under the skin. If you already have calluses and black spots you will have to keep increasing how deep the needle needs to go, making the problem even worse.
Tip 4: Find it difficult to draw blood during the cold winter months?
Warm your hands first to increase blood supply to the fingertips. Wash them in warm water then hang your hand down to allow the blood to pool in the fingertips. Try not to squeeze vigorously to get enough blood as this can prevent flow, try ‘milking the finger’ instead - squeeze from the base and move up the finger.
If you’re not convinced that a result is correct, check the following:
- Have the strips expired?
- Is the strip the correct one for the meter?
- Is there enough blood on the strip?
- Has the strip been put into the meter the right way?
- Have the strips been affected by climate, heat or light?
- Did you wash and thoroughly dry your hands before doing a check? Handling sweet foods such as jam or fruit can give higher results
- Is the meter clean?
- Is the meter too hot or too cold?
- Is the battery low or flat?
All monitors will give a different result with a different drop of blood. As long as there is not a big difference (more than 2mmol/L) there is not usually cause for concern.
How often should you replace your monitor?
Replacing your monitor every four to five years is generally recommended as good practice. However, if your readings seem erratic or inconsistent you may want to replace it earlier. Talk to your diabetes educator or GP for advice.