Why It Is Done

Blood glucose tests are done to:

• Check for diabetes.
• Monitor treatment of diabetes.
• Check for diabetes that occurs during pregnancy (gestational diabetes).
• Determine if an abnormally low blood sugar level (hypoglycemia) is present. A test to measure blood levels of insulin and a protein called C-peptide may be done along with a blood glucose test to determine the cause of hypoglycemia. For more information, see the topic C-Peptide.

Fasting blood glucose tests are done to detect the risk of diabetes (prediabetes) when glucose levels are 110–125 mg/dL (5.6–6.9 mmol/L), as recommended by the American Diabetes Association.¹