What is a blood glucose test for children?
A blood glucose test measures the amount of a type of sugar (glucose) in your child's blood. A few types of tests are used.
- Fasting blood sugar (FBS) measures blood glucose after your child has not eaten for at least 8 hours. It is often the first test done to check for prediabetes and diabetes.
- Random blood sugar (RBS) measures blood glucose no matter when your child last ate.
Why is a blood glucose test done in children?
Blood glucose tests are done to:
- Check for diabetes.
- Check your child's blood glucose level if your child is sick or planning to be more active.
- See how well treatment for diabetes is working.
How is a blood glucose test done?
A health professional uses a needle to take a blood sample, usually from an arm.
How do you prepare for a blood glucose test?
Fasting blood sugar (FBS)
For a fasting blood sugar test, do not eat or drink anything other than water for at least 8 hours before the blood sample is taken.
If you have diabetes, you may be asked to wait until you have had your blood tested before you take your morning dose of insulin or diabetes medicine.
Random blood sugar (RBS)
No special preparation is needed before having a random blood sugar test.
What do the results of a blood glucose test mean?
Normal
Results are often ready in 1 to 2 hours. Glucose levels in a blood sample taken from your vein (called a blood plasma value) may differ a little from glucose levels checked with a finger stick.
Each lab has a different range for what's normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn't in the normal range may still be normal for you.
High values
You may have diabetes. To make a diagnosis of type 2 diabetes, your doctor will use the American Diabetes Association's criteria.
Other conditions that can cause high blood glucose levels include:
- Severe stress.
- Heart attack.
- Stroke.
- Cushing's syndrome.
- Medicines such as corticosteroids.
- Excess production of growth hormone (acromegaly).
Low values
A fasting glucose level below 55 mg/dL that is accompanied by symptoms of hypoglycemia may mean you have an insulinoma, a tumor that produces abnormally high amounts of insulin.
Low glucose levels also may be caused by:
- Certain noninsulin medicines.
- Drinking too much alcohol.
- Liver or kidney disease.
- A tumor in the pituitary gland.
- A severe infection.
- Malnutrition or an eating disorder, such as anorexia.
- Medicines used to treat diabetes.
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