Blood Glucose Monitoring

Self-blood glucose monitoring is a valuable diabetes management tool, which enables people to check their blood glucose levels every day, as often as they need or as recommended.

Regular blood testing allows you to:

Develop a better understanding of the relationship between your blood glucose levels (BGL’s), the food you eat, the exercise you do and other lifestyle factors such as stress, travel and illness.
Improve your confidence in looking after your diabetes.
Find out immediately if your BGL is high (hyperglycaemia) or low (hypoglycaemia). This will help you to make important decisions such as treating a low blood sugar level or eating before you exercise.
Know when to seek advice from your diabetes health professional about adjusting insulin, tablets, meals or snacks when your BGL goals are not being met.

What blood glucose levels do I aim for?

Diabetes self-management is all about achieving a balance between the food that you eat, your activity levels and the medication that you take. This is sometimes hard to balance, it can be difficult to obtain ideal blood glucose levels all of the time.

Targets for blood glucose control
Risk of hypoglycaemia	Less than 3mmol/L* if insulin or specific diabetes tablets are used. This does not apply to people who are controlled by eating healthy and exercise alone
Population without diabetes	4 – 6 mmol/L* before meals 4 – 8 mmol/L* after meals
Ideal blood glucose levels	4 – 6 mmol/L before meals Up to 8 mmol/L after meals**
Moderate blood glucose levels	6 – 7 mmol/L before meals Up to 11 mmol/L after meals**
Above target blood glucose levels	More than 7 mmol/L before meals More than 11 mmol/L after meals**

* In Australia, blood glucose levels are measured in mmol/L (millimoles per litre). In some countries, the unit of measurement is mg/dL (milligrams per decilitre).
** Measured two hours after starting the meal.

Targets are taken from Diabetes and You – the Essential Guide, published by Diabetes Australia 1999, revised 2002.

When to test?

This needs to be decided with your diabetes health professional. Record your levels in a diary and take them with you to all appointments. Most blood glucose meters have software that enables you to download readings onto charts or graphs.

Guidelines for people with type 1 diabetes

Test at least three – four times per day is recommended. Many people with type 1 diabetes test more often, such as those using a pump.
Test before breakfast (fasting), before lunch, before dinner and at bedtime.
Test occasionally between 2am and 3am to assess an overnight level.
Test 2 hours after any meal.

Guidelines for people with type 2 diabetes

Test once or twice daily, changing the time of day at which the test is done or as directed by your Doctor or Diabetes Educator.
Suggested times to choose from are:
         - before breakfast (fasting)
         - two hours after any meal
         - before bed.

You may need to test more often when you are:

sick or stressed
changing your usual routine or eating habits eg travelling
changing your medications and/or insulin
experiencing hypoglcaemia (low blood glucose)
experiencing hyperglycaemia (high blood glucose)
experiencing night sweats or morning headaches
being more physically active or less physically active

A quick checklist if you are not sure the result is correct

is the strip the right one for the meter?
has the strip been put into the meter the right way?
have you washed and dried your hands thoroughly before doing the test ?
is the meter clean?
is the battery low or flat?
have the strips been affected by climate, heat or light due to the cap being left off?
is the calibration code correct?
is the meter too hot or too cold?
is there enough blood on the strip?
have the strips expired?

Control solutions are provided for all meters to check for accuracy. Once opened the control solution can be used for up to three months. Diabetes SA will perform this test for you free of charge.

What is a glycosylated haemoglobin (HbA1c) test?

The HbA1c is a slow continuous process in which glucose attaches itself to the haemoglobin (red blood cells) and remains there for approximately 120 days. The HbA1c gives an average of the blood glucose level over the past 10 – 12 weeks. It is measured as a percentage. The ideal range is 7% or below, but this may be higher for children, the elderly and the frail. Your doctor will provide you with advice.

This test is not the same as recording your own BGL’s as it does not show the highs and lows. It therefore does not replace the tests that you do but is used as an added tool in giving an overall picture of your blood glucose management.