Oral Glucose Tolerance Test

What is an oral glucose tolerance test?

A glucose tolerance test shows how your child’s body handles sugar (glucose). The test shows if your child has high or low blood sugar after eating.

The test takes place at the Endocrine Clinic and lasts about 2 hours.

Your child will need to follow fasting guidelines or NPO guidelines for when to stop eating and drinking. Stop giving them solid food, enteral (tube) feeds, and liquids 8 hours before the time of their test. They can continue to drink water.
Give your child their usual medicine(s) the morning of the test unless the care team tells you not to do so.
Have your child wear comfortable clothes.
Bring activities such as books, games, or tablets that they can do during the test.

You can stay with your child during the test.
Before the test, the care team will place an IV in your child’s arm.
The care team will give your child a sweet liquid (glucose solution) to drink over 5 minutes.
Before and every 30 minutes during the test, the care team will draw blood samples through the IV. They will draw blood samples for a total of 2 hrs. The lab will measure the amount of glucose in your child’s blood samples.
A nurse will check your child’s vital signs during the test.
At the end of the test, the nurse will remove the IV.

After drinking the sugary drink, your child may feel nauseated for a short time. Your child should not have other side effects after the test.

Your child can return to normal activities after the test.

A glucose tolerance test shows how your child’s body processes sugar.
For this test, the care team will give your child a sweet liquid (glucose solution) to drink.
The nurse will take blood samples to measure the amount of glucose in your child’s blood over time.
Your child should not have any side effects after testing other than nausea for a short time.

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Reviewed: June 2023