How is diabetes diagnosed?

Diabetes is diagnosed base upon the level of your blood sugar and this definition has not changed even with the recent change in the new Canadian Diabetes Associations guidelines. Diabetes is defined as having a blood sugar in the fasting state (that means before eating a meal) greater than 7mmols/L. If your blood sugar is 7 mmols/L or greater that is diabetes. However, there are certain conditions which can occur well before that. For example, a normal person should not have a blood sugar in the fasting state greater than 6.1 mmols/L. If you measure your blood sugar and it is between 5.7- 6.9 mmols/L, your doctor then should do an additional test because it may not be a normal situation.
If your blood sugar is between 5.7 mmols/L and 6.9 mmols/L when measured fasting, your doctor should give you a 75 gram sugar drink and then test your blood sugar two hours later. If the value, two hours after drinking that sugar drink is 11.1 mmols/L or greater, you actually have diabetes, even though your fasting glucose was normal. If on the other hand, two hours after drinking the sugar drink your blood sugar is between 7.8 and 11.1 mmols/L, you do not have diabetes but you have “Impaired Glucose Tolerance”. This is a pre-diabetic state that has a high risk of developing diabetes and also a high risk of developing heart disease. If on the other hand, when you do a fasting glucose, it is between 6.1 and 6.9, you do not have diabetes but you have something wrong and that is called “ Impaired Fasting Glucose”. An impaired fasting glucose state is also a predictor that you are going to develop diabetes in the future and also represents a higher risk for heart disease.
Finally, if you have symptoms of diabetes such as excessive thirst, excessive urine, frequency of urination and getting up at night to pass urine, these are the early symptoms of diabetes. They only occur when your blood sugar is over about 10 mmols/L. If you have symptoms of diabetes and your doctor measures the fasting glucose or glucose at anytime of the day even after eating and it is greater than 11.1 mmols/L, you still can be diagnosed with diabetes just by that one test.