Hemoglobin A1c (HbA1c) by High-Performance Liquid Chromatography (HPLC)
This test measures the average level of hemoglobin A1c in your blood over the past 2–3 months, reflecting your blood sugar control during that time.
["HbA1c helps doctors assess how well your diabetes or prediabetes is managed."]
Key facts at a glance
- LOINC
- 76768-1
- Short code
- Hgb BldMV Oximetry-mCnc
- Synonyms
- Hgb BldMV Oximetry-mCnc
- Category
- hematology
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 12
- Ref high
- 17.5
- Critical range
- 7 N/A – 20 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- oximetry
- CPT
- 85018
- SNOMED
- 900000000000003004
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why is HbA1c important?
HbA1c provides a snapshot of your blood sugar levels over time, which can help prevent long-term complications like nerve damage, kidney disease, or heart disease. Unlike daily blood sugar checks, it gives a clearer picture of your average glucose levels.
How is HbA1c measured?
This test uses a specialized machine called high-performance liquid chromatography (HPLC) to separate and measure hemoglobin molecules based on their sugar attachment. The result is expressed as a percentage of total hemoglobin.
What does an HbA1c result mean?
Results are typically reported as a percentage (e.g., 5.7%, 6.5%, 7.8%). A result below 5.7% is generally considered normal, while 5.7%–6.4% suggests prediabetes, and 6.5% or higher indicates diabetes. Your doctor will interpret results based on your overall health and medical history.
What can affect HbA1c results?
Several factors can influence HbA1c levels, including recent blood sugar fluctuations, pregnancy, certain medications (like insulin or oral diabetes drugs), blood loss, or iron deficiency. If you suspect these factors may affect your result, discuss them with your healthcare provider.
Reference range
Adult males: 13.5-17.5 g/dL; Females: 12.0-16.0 g/dLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical significance of HbA1c
Short name
HbA1c
Frequently asked questions
How often should I get an HbA1c test?
What does an abnormal HbA1c result mean?
Can HbA1c be affected by diet or exercise?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy