Why are tools for checking blood sugar so important?
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Blood
glucose monitoring is very important because it checks the blood sugar balance and
diabetes control.
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Urine checking tells you whether there are sugar and
ketones in the urine.
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Checking blood for
hemoglobin A
1c, (HbA
1c or A
1c) shows diabetes control over a 3-month period.
You should become familiar with these tools. They are useful only when they are used accurately and interpreted wisely.
Blood glucose meters
Since about 1980 people with diabetes have been able to check their blood sugar levels at home. This may not be as precise
as laboratory methods, but it is accurate enough for daily checks of diabetes control. The most common way to do home checking
is with a blood glucose meter. Meters need a drop of blood from a finger prick. A few methods, but not all, allow for taking
the blood sample from another site such as the forearm.
Once a small drop of blood is applied to a special part of the test strip, the meter is able to give a quick, accurate reading,
when used correctly. There are a number of factors to think about when you get a blood glucose meter.
Lancing devices are tools that cause a tiny needle, called a lancet, to prick the finger to get a drop of blood. This is done
at the touch of a button. The actual lancet is a small plastic insert with a very short needle-tip end. The tips come in different
sizes or gauges. The higher the gauge, the finer the point. This helps to get a blood sample less painfully. Even young children
may be able to take their own blood samples, with adult supervision. To avoid spreading infections, your lancing device should
not be used on anyone else.
Things to consider before getting a blood glucose meter
When you get a glucose meter, there are a number of factors to consider. Most importantly, does your diabetes team have confidence
in the accuracy of this meter? Other possible factors are:
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the size of the meter and whether it’s easy to take to school or other places
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the time needed to do a blood test
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how much blood is needed to get a reliable test result
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how easy it is to use the meter
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what error messages you get if there is a problem with the test strip
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how easy it is to adjust (calibrate) the meter if necessary
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whether the meter has a memory to store results
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whether the results can be downloaded to a computer
Whatever meter you prefer, consider how firmly the manufacturer stands behind its product. Does it provide a toll-free number
for questions and technical support?
Most glucose meters come as a kit. The kits typically will include a lancing device, a few check strips, control solution,
and a carrying case.
Making sure the reading is accurate
The glucose meter should be checked regularly with the check strips and control solution that come with the system. A blood
glucose test should be done, on the same sample, both in the lab and by your meter to check its accuracy at every visit if
possible but at least once or twice a year. Results of the meter test should be within 10% to 15% of the lab test. For example,
if the lab reading is 10 mmol/L (180 mg/dL), the meter result should be between 8.5 and 11.5 mmol/L (150-210 mg/dL).
Checking urine
For sugar
Sugar in the urine is usually checked only as a back-up to checking blood sugar, or to screen other family members. A chemically
treated strip is dipped briefly into a fresh urine sample. The strip will change colour. After a certain period of time the
strip will be compared with a colour chart on the box.
A urine check showing no sugar means that when the urine was made the blood sugar level was below the renal (kidney) threshold
(about 8.0-12.0 mmol/L, or 145-220 mg/dL).
A urine check showing sugar means that when the urine was made the blood sugar was above the renal threshold (about 8.0-12.0
mmol/L, or 145-220 mg/dL).
These urine checks are not a direct measure of blood sugar, because the urine collected for the test may have been produced
over a number of hours.
Checking urine for sugar is most useful as a screening tool for other members of the family, if they show signs of diabetes
such as urinating often and too much.
For ketones
Urinary ketones are checked by dipping a chemically treated strip in a fresh sample of urine. The colour change is then compared
to a chart. A purple colour means ketones are in the urine. Ketones are a sign that too much fat has broken down in the body.
There may be a number of causes, such as too little insulin or the stress of an illness.
Check urine ketones whenever:
Have strips at home for ketone checking at all times. Make sure that the strips have not expired by checking the expiration
date on the bottle. The bottle should be kept closed.
Some meters use strips that can also check for ketones as well as glucose. Follow the instructions on the package carefully,
and ask your health care team for help if the instructions are not clear.
