Hemoglobin A1c (HbA1c) measured 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.
["HbA1c helps doctors assess long-term diabetes management and adjust treatment plans."]
Key facts at a glance
- LOINC
- 723-7
- Short code
- Hgb Prt-mCnc
- Synonyms
- Hgb Prt-mCnc
- 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 Is HbA1c Used For?
HbA1c is primarily used to diagnose diabetes, monitor blood sugar levels over time, and evaluate how well diabetes treatments are working. It’s a key indicator of your body’s ability to manage glucose (sugar) in the blood, even if your current blood sugar levels are normal.
How Is HbA1c Different from Daily Blood Sugar Checks?
Unlike daily blood sugar tests (like fingerstick glucose checks), HbA1c gives a broader picture of your average blood sugar over months. It accounts for fluctuations that daily tests might miss, making it a reliable measure for long-term health.
Why Is HbA1c Important for People Without Diabetes?
Even if you don’t have diabetes, HbA1c can help identify prediabetes or early signs of blood sugar issues. Regular monitoring can help prevent complications like nerve damage or heart disease.
How Often Should I Get an HbA1c Test?
Doctors typically recommend HbA1c testing every 3–6 months for people with diabetes. Others may test annually or as advised by their healthcare provider, depending on risk factors.
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.
HbA1c is a critical tool for diagnosing diabetes (when levels are ≥6.5%) and assessing prediabetes (4.0%–5.6%). Lower-than-normal levels (below 5.7%) suggest good blood sugar control. Repeatedly high or low HbA1c can signal underlying conditions like insulin resistance or poor medication adherence, guiding necessary lifestyle or treatment changes.
Short name
HbA1c
Frequently asked questions
What Does an HbA1c Test Involve?
How Does HbA1c Compare to Other Blood Sugar Tests?
Can HbA1c Results Be Affected by Other Factors?
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