HbA1c (Glycated Hemoglobin)
Also known as: Hemoglobin A1c, Glycohemoglobin, Glycated Hb, A1c Test
Parameters Measured in the Report
A breakdown of individual biomarkers and biological reference intervals typically found in your report:
| Biomarker | Standard Range | Unit | What It Means |
|---|---|---|---|
HbA1c (Percentage) (A1c) | Normal: < 5.7 Prediabetes: 5.7–6.4 Diabetes: ≥ 6.5 | % | Standard percentage metric established by the American Diabetes Association (ADA). |
HbA1c (IFCC Units) (IFCC HbA1c) | Normal: < 39 Prediabetes: 39–47 Diabetes: ≥ 48 | mmol/mol | International Federation of Clinical Chemistry standard reporting unit. |
Estimated Average Glucose (eAG) (eAG) | Normal: < 117 Prediabetes: 117–137 Diabetes: ≥ 140 | mg/dL | Calculated translation of your HbA1c percentage into everyday blood sugar reading units. |
* Note: Reference ranges may vary slightly between testing instruments and reagent kits. Always refer to the reference interval printed on your specific pathology report.
Clinical Focus
Percentage of hemoglobin molecules chemically bound to glucose over the past 2 to 3 months.
Sample & Specimen
Venous blood (EDTA tube)
Fasting Protocol
No fasting required. You can take this test at any time of day, regardless of meals.
Turnaround Time
6–24 hours
What Is This Test?
Why Did Your Doctor Order This Test?
Physicians routinely prescribe the HbA1c in the following clinical scenarios:
How to Prepare Before Your Test
- No fasting is necessary. Eating or drinking before the test will not affect the HbA1c percentage.
- Take your regular prescription medications unless instructed otherwise by your treating doctor.
- Inform your doctor if you have hemoglobin variants (e.g., sickle cell trait, thalassemia) or severe anemia, as these can affect HbA1c accuracy.
Understanding Your Results
What higher or lower readings generally mean in clinical practice:
If Values Are Higher Than Normal
An HbA1c of 5.7% to 6.4% indicates prediabetes, meaning your risk of developing full Type 2 diabetes and cardiovascular disease is significantly elevated. An HbA1c of 6.5% or higher on two separate occasions confirms diabetes. In diagnosed diabetics, values above target (>7.0%–8.0%) suggest treatment adjustment is needed.
If Values Are Lower Than Normal
Unusually low HbA1c (<4.0%) is uncommon and usually not caused by true hypoglycemia; it is frequently linked to conditions with shortened red blood cell lifespans, such as hemolytic anemia, recent severe blood loss, or frequent blood transfusions.
Frequently Asked Questions
Why did my doctor order both Fasting Blood Sugar and HbA1c?
Fasting sugar shows your acute baseline glucose level today, whereas HbA1c shows your 3-month average. Together, they provide both immediate and long-term clarity on glucose metabolism.
What is the target HbA1c for someone already diagnosed with diabetes?
For most non-pregnant adults with diabetes, the general target is under 7.0% (<53 mmol/mol). However, physicians individualize this target based on age, hypoglycemia risk, and existing cardiovascular conditions.
Related Laboratory Tests
Tests frequently prescribed together or used as follow-up investigations:
Fasting Blood Sugar (FBS) & PPBS
Immediate concentration of glucose in the bloodstream after an overnight fast and post-meal.
Fasting Serum Insulin & HOMA-IR
Fasting blood insulin concentration and calculated mathematical Homeostatic Model Assessment of Insulin Resistance.
Lipid Profile (Cholesterol Panel)
Total Cholesterol, HDL (good cholesterol), LDL (bad cholesterol), VLDL, and Triglycerides.
Urine Microalbumin / Albumin-to-Creatinine Ratio (UACR)
Microscopic leakage of albumin protein standardized against urine creatinine excretion.
Medical & Diagnostic Disclaimer
This guide is published for educational and patient informational purposes only. It is not a substitute for professional medical evaluation, diagnosis, or clinical advice.
A laboratory result that falls slightly outside standard statistical reference intervals does not automatically indicate disease; conversely, a normal result does not guarantee the absence of medical conditions. Only your attending physician can interpret lab findings in the context of your medical history, physical exam, and symptoms.