What is the
blood glucose test?
This test measures the amount of glucose
(sugar) in the blood. Sugar is an important source of
energy, especially for the brain. The amount of glucose in
the blood is carefully controlled by the endocrine
(glandular) system. This system causes sugar to be stored or
used for energy, depending on the needs of your body.
You can get glucose directly from some
foods, such as table sugar. The body can also produce
glucose when other foods, such as bread and cereal, are
digested.
Why is this
test done?
The most common use of the blood glucose
test is to check for diabetes mellitus. The test is also
used to see how well the body is metabolizing glucose and
the function of organs involved in that process: the
pancreas, the liver, and the receptors that bring glucose
into cells.
How do I
prepare my child for this test?
Your child usually does not need to fast or
limit his or her activity before the first test.
If your child's first test is abnormal, a
health care provider may ask your child to fast before
repeating the test. The fasting test will show whether the
abnormal result in the first test was caused by food your
child ate before the test or some other reason.
The simplest way to check for diabetes is to
check blood sugar (glucose) before anything is eaten in the
morning. In most cases, your child will fast overnight,
eating nothing and drinking nothing but water after an
evening meal, and in the morning his or her blood is drawn.
Your child may need to avoid taking certain
medicines before the test because they might affect the test
result.
Talk to your child's health care provider if
you have any questions.
How is the
test done?
Your child's health care provider will poke
a finger with a lancet and fill a small tube with the blood.
Sometimes blood is taken from your child's arm through a
needle instead of using a finger poke. The blood is
collected and sent to a lab. Having this test will take just
a few minutes.
How will I
get the test result?
Ask your health care provider how you will
get the result of your child's test.
What does the
test result mean?
The normal fasting blood glucose range for
children in most labs is 60 to 100 milligrams per deciliter
(mg/dL). The normal range may vary slightly from lab to lab.
Normal ranges are usually shown next to the results in the
lab report. A fasting blood sugar level of 126 mg/dL or
higher can mean your child has diabetes.
Blood glucose level may be
higher than normal (called
hyperglycemia) if:
- Your child has diabetes mellitus and:
- diabetes medicines are not
adequately controlling the condition
- your child hasn't been following a
diabetic diet.
- Your child has kidney or liver
disease.
- Your child's pancreas is inflamed.
- Your child's body is severely stressed
from a bad infection or injury.
Your child's blood glucose level may be
lower than normal (called
hypoglycemia) if:
- Your child is diabetic and:
- the dose of insulin or other
medicine used to control the diabetes is too high
- your child took medicine for
diabetes but then did not eat.
- Your child's thyroid, pituitary, or
adrenal glands are not working normally.
- Your child has liver disease, problems
absorbing food, or a diet low in needed nutrients.
What if my child's test result is not normal?
Test results are only one part of a larger
picture that takes into account your child's medical history
and current health. Sometimes a test needs to be repeated to
check the first result. Talk to your health care provider
about the result and ask questions.
