How does one get diagnosed with diabetes?
1) One of the other tests that might be done is the oral glucose tolerance test (OGTT) which you can read more about here. Because this test is more time intensive and costs more it has fallen out of favor, particularly at the hospital where I work that serves a population that has to drive far and wide to get their primary care. The advantage of this test though, is that if you have noticed "normal" fasting levels but you have seen high "post meal" levels, looking at your post-meal response can actually catch a blood glucose problem early and you can start your intervention earlier.
2) Some of the warning signs that you will often see on diabetes awareness posters include the excessive thirst, excessive urination, and excessive hunger that I discussed yesterday. These symptoms are most common in Type 1 diabetes which tends to have a more rapid onset, but people with Type 2 can develop these symptoms as well. Unfortunately, a person can actually have blood glucose levels in the "diabetic" range before these symptoms develop, and the evidence points to intervening early on to prevent complications of diabetes. The American Diabetes Association recommends that individuals 45 and over get screened (by looking at the fasting blood glucose) initially at age 45 and then every 3 years. Some people can get screen at a younger age if you have a parent or sibling with the disease, have a "constellation" of problems like high blood pressure/heart disease/high cholesterol levels, and/or are overweight or obese as defined as having a BMI over 25. (I know, I know. Here's a link back to my other post about better ways to examine weight.)
3) If your physician/provider notices a problem with the blood glucose levels, I recommend using that as a wake-up call to change your eating habits to prevent future complication. Sometimes a person in a high risk group might actually be given medication to help combat the high blood glucose levels, but that is between the individual and his/her medical provider.