Hemoglobin A1c (HbA1c) with mass fraction measurement 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 long-term diabetes management and adjust treatment plans."]
Key facts at a glance
- LOINC
- 56476-5
- Short code
- Hgb S MFr DBS
- Synonyms
- Hgb S MFr DBS
- Category
- hematology
- Sample
- serum
- Container
- Red-top tube (SST)
- 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
- CPT
- 85018
- SNOMED
- 900000000000003004
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What HbA1c Test Measures
HbA1c is a form of hemoglobin (the protein in red blood cells that carries oxygen) that has attached a sugar molecule (glucose). The test quantifies this attachment to gauge how consistently your blood sugar has been within target ranges over time. Unlike spot blood sugar checks, HbA1c provides a broader picture of your metabolic health.
Why It’s Used
Doctors use HbA1c primarily to diagnose diabetes, monitor its progression, and evaluate whether current treatments are effective. It’s especially useful for people with type 1 or type 2 diabetes, as well as those at high risk for prediabetes.
How It Works
Your blood sample is analyzed using HPLC, which separates hemoglobin variants based on their sugar content. The test detects the proportion of hemoglobin A1c relative to total hemoglobin, expressed as a percentage.
Sample Preparation
A small blood sample is drawn from a vein, typically in your arm. The sample is processed and sent to a lab for HPLC analysis. No special preparation is needed, but fasting is not required.
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.
◆Associated findings1
Short name
HbA1c
Frequently asked questions
How often should I get an HbA1c test?
What do my HbA1c results mean?
Can lifestyle changes affect HbA1c results?
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