Undiagnosed diabetes

Is it possible that the number of people suffering from diabetes is woefully under-diagnosed?

I was diagnosed with diabetes in March of this year. Apparently my Type 2 Diabetes should have been diagnosed last August, but, somehow, the very high blood sugar level was overlooked and no action was taken.

However, my wife -herself a diabetic- was convinced that I was suffering from diabetes for at least the past five years, but although doctors tested my blood glucose levels they apparently gave no cause for concern.

So, are the current tests for diabetes inadequate?

If my case is typical, then there must be a large number of people who are suffering with untreated diabetes. Which, potentially, is putting them at risk from a variety of health conditions that can be linked to diabetes, such as gangrene, vision loss, etc.

What can the medical profession do to correct this problem?