What HbA1C value indicates a diagnosis of diabetes?

A HbA1C value of 6.5% or higher is foundational in diagnosing diabetes, according to clinical guidelines. This test measures the average blood glucose levels over the past two to three months, providing a reliable indication of long-term glucose control. When the HbA1C level reaches 6.5% or more, it signifies that the patient may have consistently high blood sugar levels, which is a hallmark of diabetes.

Considering values below 6.5%, such as 6.0% or any value below it, typically suggest that the individual is either within the normal range or in a state that could indicate prediabetes, but not diabetes itself. Therefore, to establish a diagnosis, a level of 6.5% has to be met or exceeded. The higher values mentioned, like 7.0% or 7.5%, are generally made in the context of managing diabetes rather than diagnosing it specifically, as they would indicate poor glycemic control in someone already diagnosed.