Diabetes is often called a “silent disease” because it can cause serious complications without symptoms. A person with diabetes may feel healthy and still have too high a level of blood glucose. It is important to know how well you are managing your blood glucose level. Knowing your Hemoglobin A1C, or average blood glucose, helps you to see how well you are managing your diabetes over time.
Adams, Ingrid, "Diabetes and Hemoglobin A1C" (2010). Family and Consumer Sciences Publications. 4.