Hemoglobin A1c levels over 7 percent indicate uncontrolled diabetes, which is associated with complications from the disease, according to Mayo Clinic. The higher a patient's A1c levels, the more likely he is to experience diabetic complications. Complications from diabetes include blindness and lower limb amputation, according to the International Diabetes Federation.
Normal hemoglobin A1c levels range between 4.5 to 6 percent with higher levels indicating prediabetes or diabetes, according to Mayo Clinic. Hemoglobin A1c indicates blood sugar control over a few months, and higher percentages of hemoglobin A1c are associated with higher average blood sugar levels, according to WebMD. An A1c level of 8 percent is indicative of long-term uncontrolled diabetes, states the Mayo Clinic.
Uncontrolled diabetes contributes to cardiovascular disease that is the leading cause of death for diabetics, states the International Diabetes Federation. Sustained high blood glucose such as that indicated by high A1c levels is a risk factor that increases the chance of a diabetic developing risk of cardiovascular complications such as stroke and coronary artery disease.
Two consecutive hemoglobin A1c results of 6.5 percent or higher are considered as diagnostic criteria for diabetes, states the Mayo Clinic. A1c levels between 5.7 percent and 6.4 percent indicate a prediabetic condition, according to WebMD. Some people have conditions, such as anemia or bleeding, that contribute to falsely high or low hemoglobin A1c results, according to Mayo Clinic. People with Mediterranean, African and Southeast Asian heritage are more likely to have hemoglobin variants and may need hemoglobin A1c testing to be performed at a special lab for accurate results.