Checking Blood Glucose Levels
When a
person's body is operating normally, it automatically checks the level of
glucose in blood. If the level is too high or too low, the body will
adjust the sugar level to return it to normal. This system operates in
much the same way that cruise control adjusts the speed of a car. With
diabetes, the body doesn't do the job of controlling blood glucose
automatically. To make up for this, someone with diabetes has to check
blood sugar regularly and adjust treatment accordingly.
| Points to Remember
- Testing blood glucose levels regularly can show whether
treatment is working.
|
A doctor can measure blood
glucose during an
office visit. However, levels change from hour to hour
and someone who visits the doctor only every few weeks won't know what his
or her blood glucose is daily. Do-it-yourself tests enable people with
diabetes to check their blood sugar daily.
The easiest test someone can do at home is a urine test. When the level
of glucose in blood rises above normal, the kidneys eliminate the excess
glucose in urine. Glucose in urine, therefore, reflects an excess of
glucose in blood.
Urine testing is easy. Tablets or paper strips are dipped in urine. The
color change that occurs indicates whether blood glucose is too high.
However, urine testing is not completely accurate because the reading
reflects the level of blood glucose a few hours earlier. In addition, not
everyone's kidneys are the same. Even when the amount of glucose in two
people's urine is the same, their sugar levels may be different. Certain
drugs and vitamin C also can affect the accuracy of urine tests.
It's more accurate to measure blood glucose directly. Kits are
available that allow people with diabetes to test their blood glucose at
home. The test involves pricking a finger to draw a drop of blood. A
spring-operated "lancet" does this automatically. The drop of blood is
placed on a strip of specially coated plastic or into a small machine that
"reads" how much glucose is in the blood. A doctor may suggest that
someone test his or her blood glucose several times a day. Self blood
glucose monitoring can show how the body responds to meals, exercise,
stress, and diabetes treatment.
Another test that measures the effectiveness of treatment is a
"glycosylated hemoglobin" test. It measures the glucose that has become
attached to hemoglobin, the molecule in red blood cells that gives blood
its red color. Over time, hemoglobin absorbs glucose, according to its
concentration in blood. Once glucose is absorbed by hemoglobin it remains
there until the blood cells die and new ones replace them. With the
"glycosylated hemoglobin" test, a doctor can tell whether blood glucose
has been very high over the last few months.