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An oral glucose tolerance test measures the body's ability to
use glucose, a type of sugar found in fruits and many other foods. (Glucose is
the main source of energy used by the body.)
After not eating all
night, the person being tested drinks a special sugar solution on the morning
of the test. A blood sugar sample is taken from a vein in the person's arm once
each hour for several hours to see how much the blood sugar increases and then
decreases over time. The test is done in a doctor's office or lab.
The oral glucose tolerance test can be used to diagnose prediabetes and
diabetes. It is used to diagnose gestational diabetes, which may develop
Current as of:
November 14, 2014
E. Gregory Thompson, MD - Internal Medicine & Alan C. Dalkin, MD - Endocrinology
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