Diagnosis

How diabetes is diagnosed

Most people with type 1 diabetes and many with type 2 diabetes will present with symptoms of diabetes. However some people with type 2 diabetes may have no symptoms at all.

Diabetes is diagnosed when:

• Symptoms of diabetes are present and a random (non fasting) blood glucose level is equal to or greater than 11.1mmol/L.
• A fasting blood glucose level is equal to or greater than 7mmol/L.
• 2 hour blood glucose level is equal to or greater than 11.1mmol/L during an oral glucose test.

What if my blood test is not normal, but not diabetes either?

Some people will have a fasting blood level that is above the normal range, but not high enough to be diagnosed as diabetes. For example, a fasting blood glucose level that is between 5.5mmol/L and 6.9mmol/L is above the normal range but does not confirm or rule out diabetes or pre-diabetes. In this situation your doctor should order an oral glucose tolerance test (OGTT).

Oral Glucose Tolerance Test (OGTT)

What is an OGTT?

An OGTT involves a blood test taken from a vein, usually the arm, at a pathology laberatory.

What you need to do before a OGTT test

• Three days before you should have an adequate carbohydrate intake (greater than 150g per day). Examples of carbohydrate include bread, potato, fruit, rice, pasta and milk.
• You will need to fast for eight hours before the test. This is usually done overnight.
• A fasting blood glucose test is taken. You are then given a sweet drink that contains 75g of glucose.
• Your blood glucose level is checked at one hour and again at two hours after the glucose drink.

You should discuss your results with your doctor or health care team.