SOUTH SEFTON DIABETES GROUP

Blood Glucose Testing

The only way to know for sure how your treatment plan and your daily activities are affecting your blood glucose levels is to perform finger-prick blood glucose tests at key times during the day.

There are no magic formulas to tell you how your individual blood glucose level responds to food, insulin, exercise, illness and other stress. Everyone is different. By testing on a regular basis, you can generally avoid very high and very low blood glucose levels and learn how to tailor your diabetes treatment to your own lifestyle. Blood glucose testing should give you the freedom to live your life the way you want to, whilst staying fit and healthy in the long run.

As your blood glucose control improves, self-testing will give you positive feedback about your progress towards your treatment goals.

Who needs to test?

Ideally, everyone who has diabetes should monitor their blood glucose levels by self-testing.

Research has shown that many people do not test their blood glucose levels very often and some not at all. However, at the same time it was shown that testing regularly, especially for those people using insulin, could improve blood glucose control and reduce the risk of long-term complications.

If you have Type 1 diabetes, self-monitoring is crucial. If you have Type 2 or gestational diabetes and manage it with oral medication, or a diet and exercise plan, regular testing is still very important.

What do the tests show?

A single test will tell you what your blood glucose level is at that moment in time. A series of tests at different times, or on different days, will give you a pattern of your blood glucose levels over time.

Blood glucose tests can help to see how your treatment plan is working and whether you could make any alterations. They will help you fine-tune the amount of medication, food, and exercise you need.

Low results may suggest that:

• You have not enough (particularly carbohydrates), or
• You have taken too much insulin or glucose-lowering medication, or
• You have not compensated for the exercise that you have been doing

High results may suggest that:

• You have eaten too much (particularly carbohydrates), or
• You have not taken sufficient insulin or glucose-lowering medication, or
• You have been less active than usual, or
• Your body is fighting an illness or you are stressed

When should I test?

When and how often you need to test your blood glucose will depend on the type of diabetes that you have, how it is treated and what sort of lifestyle you lead. Your doctor or diabetes nurse should suggest a suitable testing regimen that is appropriate for you.

Key times to test are:

• Before meals - levels will be lowest
• 2 hrs after meals - levels will be highest
• Before bed
• 2 - 3 am occasionally (if you take insulin)

Other important times include:

• If you think your blood glucose level may be low
• Before and after exercising
• If you feel unwell
• Before driving

In general, the more often you test, the tighter you will be able to control your blood glucose levels. However, it is important that you do not become obsessed with testing. Remember though, that it is not the testing per se that improves control - it is what you do with the results that matters. See "Taking action", below.

You may need to test more often if:

• You are trying to improve your blood glucose control
• You have recently changed your treatment plan
• You suffer from frequent hypos, severe hypos, fear of hypos, or hypoglycaemia unawareness
• You are pregnant, or planning a pregnancy
• You are sick
• You are stressed
• You have lost or gained a significant amount of weight
• Your daily regimen has changed (you are more active than usual, travelling, or on holiday)

In people with Type 1 diabetes, blood glucose levels can fluctuate considerably during the day. If you are trying to keep your blood glucose as close as possible to normal levels then you should test four or five times a day: before each meal, before bedtime, and in the middle of the night (around 3 a.m.) once a week.

However, if you are on a less intensive schedule, aimed largely at preventing high blood glucose (hyperglycaemia), then you may only need to test twice a day.

If you are pregnant, then you may need to test up to seven times each day in order to get the best possible control.

People with Type 2 diabetes are often advised to test much less frequently. However, although unnecessary or inappropriate testing is a waste of time and resources, it is important that you have the tools to enable you to achieve your best possible level of health. If you are not happy with your diabetes control then discuss your current testing regimen with your doctor or diabetes nurse and see if you can agree on ways to improve the situation.

Important note: Some people believe they can tell their blood glucose level by the way they feel, but studies have shown that very few people guess their glucose level accurately. Don't rely on guesswork - it's your future health that's at stake.

How to test

A small drop of blood is usually obtained with the help of a simple finger pricking device. The drop of blood is placed on a special strip and the blood glucose level is then read by a meter.

For more information, see Meters and Finger Pricking Devices. Most blood glucose monitors come with clear instructions on how to use them. However, you should have your doctor or diabetes nurse show you how to test your blood glucose level to make sure that your technique is OK. When performed correctly, blood glucose tests are quick and easy and give accurate results.

Potential sources of error include the following:

• sticky fingers - always wash your hands before testing
• touching the test pad - handle the test strips with care
• not calibrating the meter - every batch of test strips has a special calibration code which needs to be programmed into the meter (see meter instructions for details)
• not enough blood applied to the test strip - this can give a falsely low reading
• incorrect storage of test strips (eg in bright light, damp conditions, or extremes of temperature)

Always follow the instructions provided with your meter

Blood glucose meters and finger pricking devices are available from chemist shops or directly from the manufacturer. Lancets and test strips are available on NHS prescription.

Taking action - what to do with the results

Every time you take a reading, write it down.

In order to make as much sense as possible of all your readings it will help to make a note of anything that might affect your blood glucose level. This includes:

• Any medication that you take - how much and when
• What you eat, how much you eat and when you eat it
• When you exercise, how long for and whether it is strenuous (e.g. running) or gentle exercise (e.g. walking)

Also make a note if you are under an unusual amount of stress, you are feeling under the weather, or have an infection of any kind.

The patterns in your blood glucose readings provide clues about your diabetes control. The only way to see the patterns is to record the results.

Sometimes you might find an unexpected reading; try to figure out why this might have occurred. Don't worry if there is not any obvious explanation - everyone gets the occasional high or low.

Look for patterns of highs or lows that might suggest a change is needed in your treatment plan. Your doctor or diabetes nurse will help you with this.

Don't be afraid to experiment a little. Eat an extra piece of fruit or walk an extra mile and see how it affects your blood glucose level.

Sometimes self-monitoring can be frustrating. Learn by trial and error and don't despair if things don't always go to plan. You do not need to aim for perfect control - try to find the right balance that enables you to reach your treatment goals, whilst still enjoying life to the full.