To be diagnosed with diabetes, you must meet one of the following criteria:¹

• 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).

The diagnosis of diabetes needs to be confirmed by repeating the same blood sugar test or doing a different test on another day.

If the results of your fasting blood sugar test are between 6.1 mmol/L to 6.9 mmol/L, or if your fasting blood glucose is between 5.6 mmol/L and 6.0 mmol/L and you have one or more risk factors for diabetes, you may have prediabetes. This means that your blood sugar is above normal but not high enough to be diabetes. Your doctor may recommend an OGTT to confirm. Discuss with your doctor how often you need to be tested.¹