Normal Values:

Normal blood values for a 75-gram oral glucose tolerance test used to check for type 2 diabetes:

• Fasting: 60 -100 mg/dL
• 1 hour: less than 200 mg/dL
• 2 hours: less than 140 mg/dL. Between 140 - 200 mg/dL is considered impaired glucose tolerance or prediabetes. This group is at increased risk for developing diabetes. Greater than 200 mg/dL is a sign of diabetes mellitus.

Normal blood values for a 50-gram oral glucose tolerance test used to screen for gestational diabetes:

• 1 hour: less than 140 mg/dL

Normal blood values for a 100-gram oral glucose tolerance test used to screen for gestational diabetes:

• Fasting: less than 95 mg/dL
• 1 hour: less than 180 mg/dL
• 2 hour: less than 155 mg/dL
• 3 hour: less than 140 mg/dL

Note: mg/dL = milligrams per deciliter

Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What abnormal results mean:

Greater than normal levels of glucose may mean you have diabetes or gestational diabetes.

However, high glucose levels may be related to another medical problem (for example, Cushing syndrome).