Some people can't see the point of blood glucose (sugar) testing as they think they know their glucose level simply by the way they feel. You might be surprised to know that the way you feel is not always a reliable or accurate guide as to what is happening.

Glucose testing is the process used to measure the amount of glucose in your blood. One of the ways glucose testing can be carried out is through the use of a blood glucose meter – and it is very simple to do!

A testing strip is inserted in to the meter. You then use a small lancet (finger pricking device) to get a small drop of blood from your finger which is put on the test strip. After a few seconds, the monitor will display your current glucose level.

Who should test glucose levels?

People with diabetes benefit the most from blood glucose testing when they understand their results and know what to do if their result is either too high or too low for them.

It is recommended that people who take insulin should regularly test their blood glucose levels as this can help with insulin dose adjustment. People who take tablets that can cause their glucose to fall too low, such as sulfonylureas, may also benefit from testing their glucose levels.

Not all diabetes tablets cause hypos so people that take those tablets, e.g. metformin, don’t need to test their blood glucose levels as often. However, many people with diabetes  still want to  check their blood glucose levels  to help them make decisions about the food, physical activity, driving, and their lifestyle to help maintain and improve their diabetes control.

Benefits of blood glucose testing

Blood glucose testing is a way of keeping in touch with your diabetes and being aware of high and low blood glucose levels. Knowing what affects your blood glucose levels is an essential part of good diabetes management.

If your diabetes is treated by diet or tablets, you may not need to test every day. Testing before and after some meals or before bedtime is useful particularly if your levels are not within the range you prefer. If you don’t know what your levels should be, discuss this with your diabetes nurse or doctor.

Your blood glucose testing results are useful for your doctor or nurse to see. The trends or patterns of your glucose levels can provide lots of information and can help you and your healthcare team to alter your diabetes treatment in the best way for you

Hitting targets

So, what blood glucose levels should you try to achieve? Diabetes UK has examined the medical evidence and currently recommends that people with diabetes aim for the following targets:

Everyday blood glucose

Studies have shown that keeping to these targets could significantly reduce your risk of developing diabetic complications. Some people may find these levels difficult to reach immediately. Do not feel downhearted. Any improvement could be beneficial. So, discuss a target to aim for at your clinic; they will help you to set yourself a series of goals and work step by step to bring your levels down.

To try and improve your blood glucose levels you need to regard yourself as your own laboratory. You can try a few simple experiments to see how they affect your blood glucose.

Assessing your situation

Below is some information on how to assess your blood glucose. Your healthcare professional should be your first contact for advice:

• Test your glucose levels immediately before and two hours after each meal on two days a week
• Choose one weekend day and one weekday - eating and exercise patterns are often different during the week and at weekends
• Test twice a day on all the other days, choosing different times of the day each time
• Write your results in your monitoring diary
• Download them to your computer using the software specific to your blood glucose meter
• Study the results carefully

Is a pattern emerging?

Look carefully at your results. Can you see any patterns? Are your blood glucose levels always low at a particular time of day? Or high after certain meals? When you understand what is causing the highs and lows, it is easier to correct them. Then, in the future, you will be able to use regular, everyday testing to help you to continue to keep your blood glucose well controlled

Why control your blood glucose?

Keeping your blood glucose well controlled has many benefits, including:

Avoiding hypoglycaemia
Hypoglycaemia (also commonly referred to as a hypo) occurs when your blood glucose falls too low. It is difficult to avoid hypoglycaemia completely when your diabetes is treated with insulin and, if your everyday blood glucose is fairly low, hypos may seem more of a risk.

The symptoms of a hypo vary between people, but normally include sweating, hunger, anxiety, shakes, paleness and a rapid heartbeat. If not treated, this can progress to aggressive or irrational behaviour and weakness. A severe hypo can include blurred vision, clumsiness, drowsiness or confusion and can be mistaken for drunkenness. A severe hypo will end in unconsciousness/coma and is a medical emergency.

Many people, however, find that it is the big swings in blood glucose, from very high to very low, which may lead to severe hypoglycaemia. When their blood glucose is well controlled they may feel mildly hypo slightly more often, but severe hypos are rarer.

Feeling better today
If you keep your blood glucose well controlled you may find that you feel fitter and have more energy. If your blood glucose has been high for some time this may take a few months to happen as your body may need to adjust to your new blood glucose levels, although some people feel much better almost immediately.

Reducing your risk of hyperglycaemia
There is a risk of a diabetic coma if your blood glucose levels are very high - hyperglycaemia.

Reducing your risk of future health problems
You have probably heard that, over time, diabetes can bring with it some extra health problems. Prolonged high blood glucose can damage the body, affecting the eyes, kidneys, nerves, heart and circulation. It is best that you are aware of these potential problems. Medical research, however, has shown that you can significantly reduce your chance of developing them by careful control of your blood glucose.

*Your long-term blood glucose average is measured by an HbA1c test, which your doctor or nurse will organise for you. It is a measure of how well your blood glucose has been controlled in the past six to eight weeks.