Criteria for Diagnosing Diabetes
- Have symptoms of diabetes (increased thirst, increased urination, and unexplained weight loss) and a blood sugar level equal to or greater than 11.1 millimoles per litre (mmol/L). The blood sugar test is done at any time, without regard for when you last ate (random plasma glucose test or random blood sugar test).
- Have a fasting blood sugar level that is equal to or greater than 7.0 mmol/L. A fasting blood sugar test (fasting plasma glucose) is done after not eating or drinking anything but water for 8 hours.
- Have a 2-hour oral glucose tolerance test (OGTT) result that is equal to or greater than 11.1 mmol/L. An OGTT is most commonly done to check for diabetes that occurs with pregnancy (gestational diabetes).
- Have a hemoglobin A1c that is 6.5% or higher. (This test is most reliable for adults. Some experts recommend using one of the other tests to diagnose diabetes in children.)footnote 2
Your doctor may repeat the test to confirm the diagnosis of diabetes.
If the results of your fasting blood sugar test are between 6.1 to 6.9 mmol/L, your OGTT result is between 7.8 to 11.0 mmol/L (2 hours after the beginning of the test), or your hemoglobin A1c is 6.0% to 6.4%, you have prediabetes. This means that your blood sugar is above normal but not high enough to be diabetes. Discuss with your doctor how often you need to be tested.footnote 1
- Canadian Diabetes Association Clinical Practice Guidelines Expert Committee (2013). Definition, classification, and diagnosis of diabetes, prediabetes, and metabolic syndrome section of Canadian Diabetes Association 2013 clinical practice guidelines for the prevention and management of diabetes in Canada. Canadian Journal of Diabetes, 37(Suppl 1): S8-S11. Also available online: http://guidelines.diabetes.ca.
- Canadian Diabetes Association Clinical Practice Guidelines Expert Committee (2013). Type 2 diabetes in children and adolescents section of Canadian Diabetes Association 2013 clinical practice guidelines for the prevention and management of diabetes in Canada. Canadian Journal of Diabetes, 37(Suppl 1): S163-S167. Also available online: http://guidelines.diabetes.ca.
Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
Anne C. Poinier, MD - Internal Medicine
Kathleen Romito, MD - Family Medicine
Adam Husney, MD - Family Medicine
Specialist Medical Reviewer David C. W. Lau, MD, PhD, FRCPC - Endocrinology
Matthew I. Kim, MD - Endocrinology, Diabetes and Metabolism
Current as ofDecember 7, 2017
Current as of: December 7, 2017
Author: Healthwise Staff
Medical Review: E. Gregory Thompson, MD - Internal Medicine & Anne C. Poinier, MD - Internal Medicine & Kathleen Romito, MD - Family Medicine & Adam Husney, MD - Family Medicine & David C. W. Lau, MD, PhD, FRCPC - Endocrinology & Matthew I. Kim, MD - Endocrinology, Diabetes and Metabolism
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