About Hemoglobin A1c (HbA1c)
Hemoglobin A1c (HbA1c) is a form of hemoglobin that is chemically linked to glucose. It is used as a biomarker for monitoring long-term glucose control in individuals with diabetes. HbA1c reflects the average blood glucose levels over the past two to three months, as the lifespan of a red blood cell is approximately 120 days.
Reference Values
Optimal Range
Not specified
Elite Value
4.2 %
Health Implications
{"high": "Elevated levels may indicate poor blood sugar control, increasing the risk of diabetes-related complications such as cardiovascular disease, neuropathy, and retinopathy.", "low": "Low levels may be associated with conditions such as anemia or frequent episodes of hypoglycemia, which can lead to disorientation and other complications.")
Symptoms
High
May include fatigue, frequent urination, excessive thirst, blurred vision, and headaches.
Low
Can include dizziness, sweating, confusion, shakiness, and weakness.
Lifestyle Factors
Specimen Type
Testing Methods
Also Known As
Scientific Sources
- erican Diabetes Association. (2022). 2. Classification and Diagnosis of Diabetes: Standards of Medical Care in Diabetes—2022. Diabetes Care, 45(Supplement_1), S17–S38.
- ternational Expert Committee. (2019). International Expert Committee Report on the Role of the A1C Assay in the Diagnosis of Diabetes. Diabetes Care, 42(4), 682–687.
- than, D. M., Kuenen, J., Borg, R., Zheng, H., Schoenfeld, D., & Heine, R. J. (2018). Translating the A1C Assay into Estimated Average Glucose Values. Diabetes Care, 41(8), 1786–1793.
- rld Health Organization. (2021). Use of Glycated Haemoglobin (HbA1c) in the Diagnosis of Diabetes Mellitus: Abbreviated Report of a WHO Consultation. Geneva: World Health Organization.
- cks, D. B., Arnold, M., Bakris, G. L., Bruns, D. E., Horvath, A. R., Kirkman, M. S., ... & John, W. G. (2019). Guidelines and Recommendations for Laboratory Analysis in the Diagnosis and Management of Diabetes Mellitus. Clinical Chemistry, 65(6), 766–792.