Another way to test for the level of blood glucose is by measuring the hemoglobin A1c (HA1c)level. When blood glucose levels are high, glucose attaches to hemoglobin molecules. The higher the blood glucose, the more hemoglobin molecules get “tagged” with glucose. This is an excellent test for estimating the average blood glucose level over the previous 6 weeks, and it is very helpful for monitoring a person’s diabetes. However, this test is not accurate enough for diagnosing diabetes and it should not be used for this purpose.

Once diabetes is diagnosed, how do you know what type of diabetes a person has? Additional tests are usually not needed. If the person is over the age of 30 when diabetes is diagnosed, and is overweight, has a family history of diabetes, and the diabetes has come on slowly, then he or she almost certainly has type 2 diabetes. On the other hand, the child or young adult who develops diabetes, usually with a sudden onset and accompanied by weight loss, likely has type 1 diabetes. If there is doubt as to whether a person has type 1 or type 2 diabetes, specialized testing can be done to determine whether insulin secretion is present. Gestational diabetes, of course, only occurs during pregnancy to women who were not known to have the disease previously.

Finally, who should be tested for diabetes? Certainly, anyone with symptoms of diabetes should have their blood glucose levels checked. Individuals who are at increased risk for developing diabetes should also be tested, even if they do not have symptoms.

This includes those who are over 40 and overweight, those who have a family history of diabetes, women who have had gestational diabetes, and those from ethnic groups with high rates of diabetes, such as Native Americans and those of Hispanic or African descent.