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Blood sugar levels PDF Print E-mail
Monday, 20 July 2009 10:22
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Your blood glucose level (BGL) will change every day depending on your activities, what you eat and how well your diabetes medication is working so for good diabetes management you’ll need to balance all of these elements.

You should be aiming for less than 8 mmol/l but you should discuss your own levels and targets with your doctor or diabetes educator.

As a general guide: 

Before Meals
2 Hours after meals
Good     
4-6mmol/l
up to 8mmol/l
Fair 6-8mmol/l 
up to 10mmol/l
Poor
8mmol/l or higher          
10mmol/l or higher

Glucose will generally decrease with fasting, exercise and after administering your insulin injection. And it will increase after you’ve eaten and if you’re unwell. Stress can also elevate BGL levels.

The normal ‘fasting’ range for BGLs are between 3.5 millimoles per litre (mmol/L) and 8mmol/l.

Being aware of how each of these factors affects your BLG will help you to plan your day and make adjustments to treatment to keep your diabetes stable.

It can be a difficult task to keep your diabetes stable but if your BGL is close to normal most of the time, this will help reduce diabetes complications such as heart and blood vessels damage, nerve deterioration and problems with kidneys, teeth, gums and erectile dysfunction.

At the times when there isn’t enough insulin made by the pancreas or when it isn't effective, your BGL shoots up much higher and can stay up. This higher than normal level of glucose in the blood is dangerous and can cause biochemical reactions such as ketoacidosis which is an acid (or ketone) build up and it can be fatal if left untreated.

Blood glucose testing

Blood testing your glucose level will become a familiar practice if you’re diagnosed with diabetes and will let you know how much sugar is in your blood.
Initially, to determine whether you have diabetes, a veinous blood sample, not from a finger prick, will be taken to measure the level of glucose in your blood and how well your body processes glucose.

Your doctor will tell you which type of test they will need you to take and it will be either:
  • Glucose tolerance test measure blood glucose levels eight hours after your last meal. -special diet for 2/3 days, then fast. If there is a sugar reading of seven or more then you have diabetes.
  • Random blood sugar test measures blood glucose regardless of when you last ate.

Self testing

Once you have been diagnosed with diabetes you will need to monitor your BGL closely by testing yourself with a personal blood glucose monitor.

This is an important part of diabetes management because self testing will quickly tell you if your BGL is too high (hyperglycaemia) or too low (hypoglycaemia) and it will give you a clear indication of how food, fluid, exercise, illness, stress and travel affect your BGL.

By regularly monitoring your BGL you will be able to provide your doctor you’re your BGL history allowing them to see if your treatment is working effectively and alerting you and them to any pattern changes which might indicate a need to change your diabetes management.

How to test

Personal monitors or meters come with a test strip and a small, disposable sharp pin called a lancet which is button activated to quickly pierce your skin to draw a small drop of blood from your fingertip.

The blood droplet is placed on a disposable test strip and inserted into the monitor. Within a few seconds a digital reading of your BGL will be produced.
There are blood glucose test strips available which show a colour change instead of a reading from a monitor but it’s generally more accurate to have a monitor reading.

There are many types of these monitors available including some which take blood from your arm or thigh rather than from your fingertip but fingertip blood shows glucose changes more quickly than other places. Your doctor, specialist, pharmacist, dietician or diabetes educator will give you advice on which one is the most suitable for you. They will also be able to show you how to use it correctly for an accurate reading each time you do a test.

When to test

Everyone’s needs will be different and someone who is a dance instructor will have a different testing regime to an office worker.

Normally you should test your BGL before meals or two hours after meals but be guided by what your doctor or diabetes educator says is good for your situation.

Generally, people with type 1 diabetes and people with type 2 who are being treated with insulin would be expected to measure their BGL before every meal. On some days you may need only one or two tests but on others when you aren’t feeling well or your routine has been different, four or five tests may be needed.

To know how much insulin you will need overnight, your doctor may recommend measuring your BGL in the morning before any food.
You will need to test your BGL more often if you are sick (usually every two to four hours), if you’re adjusting your insulin or tablets, or when your BGLs are high (over 15 mmol/l)

If you take insulin or tablets you doctor may recommend you test before meals and before bed. When you first start your own testing you may need up to four times a day but once your BGL settles in the normal range (3.5 - 8.0 mmol/L), this will be reduced.

Women with gestational diabetes or those who take rapid acting insulin or tablets may need to test 1½ to 2 hours after meals.

You should also test your BGL is you are feeling unwell, before exercise or sometimes during the night if you think you are getting hypoglycaemic during the night but discuss this with your diabetes educator or doctor because you may need a change of medication or a more careful watch on what you eat and do.

Accurate BGL test results

Knowing how to use your monitor properly will improve the chances of getting an accurate reading. It’s vital that test strips are not out of date or damaged and you can check this by control testing with a solution. Your doctor, pharmacist or diabetes educator will show you how this is done.

Make sure your hands are clean before testing because handling sweet food such as fruit, sweets, jam or ice cream can give a higher reading.

It’s important to have enough blood on each strip and make sure your strips are stored in a dry place and the cap is replaced immediately after each use. If they are discoloured don’t use them.

Blood glucose results

  • Hyperglycaemia or a high blood glucose level (over 8 mmol/l) can be caused by:
  • Illness or infection
  • Change of diet or irregular eating times
  • Missed dose of insulin or tablets
  • Stress
  • Not enough physical activity
  • Medications (steroids)
  • Excessive alcohol
  • Progression of diabetes – your doctor will review your medication
If you have a high blood sugar level it’s important to check for ketones in your urine as this is considered a health emergency and you should call your doctor or diabetes educator.
To treat hyperglycaemia regularly drink water, eat normally and inject your insulin as normal.

A low blood glucose level is called hypoglycaemia (less than 3.5 mmol/l) can be caused by:
  • Not enough food or eating too late (if taking tablets or insulin)
  • exercise without enough carbohydrate or adjustment of insulin dose (if taking tablets or insulin)
  • too much insulin or tablets
  • alcohol without food or excessive alcohol
To treat a mild or moderate hypo eat or drink a fast acting sugary food (carbohydrate) such as a glass of fruit juice (125-200 mls) or soft drink or cordial (125-200 mls) (not diet), glucose tablets 10-15g), sugar or honey (two-four teaspoons), four large or seven small jelly beans plus a serve of slow acting carbohydrate such as milk, bread, milk, biscuits, an apple or banana.

Glycosylated haemoglobin (HbA1c) test

Every three to six months your doctor may want you to have an HbA1c test which shows an average of your BGL over the previous 10-12 weeks.  The measurement is given as a percentage not as an mmol/l reading like a personal blood glucose monitor test.

This test won’t show your glucose highs and lows but it’s another way for your doctor to work out the best management plan for your diabetes.

It looks at the red blood cells which are continuously produced by bones and released into your circulation. Each cell collects a percentage of the glucose in the blood when it is released and lives for around 120 days. The test will catch a range of cells from the previous 120 day period with different amounts of glucose all of which will be averaged out.

The goal for this average reading is between 6.5% to 7% but for elderly people and children this will be different.

Monitoring blood glucose level (BGL)

Monitoring your BGL will tell you whether your treatment and diabetes management is working.

Keep a log book or diabetes diary to record each BGL reading because it will provide you and your doctor with accurate information each time you have an appointment or when things aren’t going well.

While most blood testing monitors have a memory, many also have software to download your readings but keeping them in a diary will enable you to record your daily activities, food, change of routine, illnesses and stress factors for each day which will help with adjusting your treatment.
Last Updated on Monday, 20 July 2009 10:49