If a person has high glucose levels due to diabetes (A1C is 6.5% or higher), this can lead to many health issues that can affect the body and organs. Managing these levels can reduce the risk of damage across the body.
Getting an early diagnosis of diabetes, as well as following a treatment plan that involves regular medical care, lifestyle changes, and medication, can help limit the effects of diabetes.
This article looks at some of the long-term complications of diabetes and how to prevent them.
https://www.medicalnewstoday.com/articles/317483
In those without diabetes, A1C levels should stay below. 5.7%. [Normal: Less than 5.7; Prediabetes : 5.7 to 6.4%, Diabetes 6.5% or higher]
Dangerous levels of A1C are 9.05% and higher. An A1C above 9% increases the risk of long-term diabetes complications like blindness, nerve damage, and kidney failure.
Under 7 % is considered good control.
https://www.verywellhealth.com/what-happens-when-a1c-is-too-high-5118384