Hi! Thank you for your question. As for measuring glucose level, there are many test that doctors’ use. These include random blood glucose levels (RBG), fasting glucose levels, oral glucose tolerance test (OGTT), and HbA1c test. I will be explaining about each test below. For each test there will be a pre-diabetic and diabetic values.

The interpretation of the values also depends if the person is symptomatic or not.
RBG is the glucose level that is taken at random whether they have eaten or not. This test measures the glucose levels in the patient’s capillaries or veins at any given time. This test is not a reliable method to check for diabetes but it is easy to perform and no prior fasting is required.

A person is considered pre-diabetic if the random blood glucose level is between 7.8 to 11.1 mmol/L. A person is symptomatic he/she will be diagnosed with diabetes if the random blood glucose value more than 11.1 mmol/L. On the other hand, if the patient is asymptomatic, a capillary random blood glucose value of more than 5.6 mmol/L warrants further testing.

As for your second question, taking your glucose level 2 hours after your meal makes it a RBG test. So as mentioned above, it depends if you are symptomatic or not. If you are symptomatic, a value of 6.8 will require further testing (venous RBG) where on the other hand, if you are asymptomatic, further testing is also required (OGTT).

Hence to be sure if you’re diabetic, further testing is required for a doctor.
OGTT is a test where you will be required to consume 75g of glucose in water. Glucose levels will be measure before and 2 hours after the drink. Usually you are required to fast overnight prior to the test.

A pre- diabetic value of OGTT is between 7.8 to 11.1 and a diabetic value is more than 11.1 mmol/L.
Among all the test done, HbA1c is the most accurate and reliable. It measures your glucose control over 3 months. It is done to diagnose and monitor glucose levels in diabetic patients.

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