Hemoglobin A2 Fraction (Quantitative)
This test measures the percentage of a specific type of hemoglobin (HbA2) in your blood, which reflects long-term glucose levels in people with diabetes.
["HbA2 helps assess diabetes control over months, not just recent blood sugar spikes."]
Key facts at a glance
- LOINC
- 55370-1
- Short code
- Hgb A2+C+E+O MFr Bld
- Synonyms
- Hgb A2+C+E+O MFr Bld
- 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
- 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 This Test Matters
HbA2 is a form of hemoglobin that carries oxygen in your blood. In diabetes, high blood sugar can alter how hemoglobin works. Measuring HbA2 helps doctors check how well your diabetes is managed over time, especially in people with type 1 or type 2 diabetes who take insulin or other diabetes medications.
How It Works
Blood is drawn from a vein in your arm and sent to a lab. The lab uses a specialized method (likely immunoassay or high-performance liquid chromatography) to separate and measure HbA2 levels as a percentage of total hemoglobin.
Sample Collection
A small needle is inserted into your arm to draw a small amount of blood. This is usually done in a doctor’s office or clinic. You may feel a slight pinch, but it’s a quick process.
What to Expect After
After the blood is drawn, you can return to your normal activities immediately. There may be a small bruise or slight discomfort at the site, but it should go away quickly. No special preparation is needed for this test.
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
Short name
HbA2
Frequently asked questions
HbA2 levels are particularly useful for monitoring diabetes because they reflect average blood sugar levels over the past 2 to 3 months. Unlike immediate glucose tests, HbA2 gives a clearer picture of long-term control, helping doctors adjust treatment plans if needed.
What causes HbA2 levels to change?
How often should I get this test?
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