Hemoglobin A1c (HbA1c) by High-Performance Liquid Chromatography (HPLC)
This test measures the percentage of hemoglobin that is coated with sugar (glycated hemoglobin), reflecting your average blood sugar levels over the past 2–3 months.
["Helps track long-term diabetes control with a simple blood test."]
Key facts at a glance
- LOINC
- 54074-0
- Short code
- Hgb F MFr DBS
- Synonyms
- Hgb F 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
Why This Test Matters
HbA1c is a key marker for managing diabetes because it provides a snapshot of how well your blood sugar has been controlled over time. Unlike daily blood sugar checks, it gives a broader picture of your health, helping doctors adjust treatments like medication or diet.
How It’s Done
A small blood sample is taken from your arm, usually during a routine visit. The sample is processed using HPLC to separate and measure the different types of hemoglobin, including the glycated form.
What It Indicates
Higher HbA1c levels suggest poorer blood sugar control, while lower levels may indicate better management. However, individual results depend on factors like diet, activity, and underlying health conditions.
Common Uses
This test is used to diagnose diabetes, monitor treatment progress, and assess long-term risks of complications like nerve damage or kidney disease.
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: Elevated HbA1c levels (typically ≥6.5%) often confirm diabetes, while lower levels (below 5.7%) may indicate normal glucose metabolism. Regular monitoring helps prevent complications by identifying trends early.
Short name
HbA1c
Frequently asked questions
How often should I get this test?
What do my results mean?
Can lifestyle changes affect 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