Hemoglobin A1c (HbA1c) with mass concentration measurement
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.
["HbA1c helps doctors track long-term diabetes control and adjust treatment plans."]
Key facts at a glance
- LOINC
- 30354-5
- Short code
- Hgb BldCoA-mCnc
- Synonyms
- Hgb BldCoA-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
- 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
What HbA1c Tests Measure
HbA1c tests specifically look at the proportion of hemoglobin molecules that have sugar molecules attached. This attachment happens when blood sugar levels are consistently high, which can damage red blood cells over time. The test doesn’t measure current blood sugar but provides a snapshot of your average glucose levels over months.
Why It’s Done
Doctors order HbA1c tests primarily to diagnose diabetes, monitor diabetes management, or assess prediabetes risk. It’s especially useful for people with type 1 or type 2 diabetes, as it helps prevent complications like nerve damage, kidney disease, or vision problems.
How It’s Performed
A small blood sample is taken from your arm, usually via a needle. The sample is then processed to separate hemoglobin and measure the glycated fraction using a specialized lab technique.
What to Expect Before or After
No special preparation is needed, but you may experience a slight pinch when the blood is drawn. Results are typically ready within a few days. If you’re diabetic, your doctor may recommend testing every 3–12 months, depending on your treatment plan.
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 marker for diabetes management. A higher percentage suggests poorer blood sugar control, while a lower percentage may indicate better management. It’s also used to identify prediabetes (typically 5.7%–6.4%) or undiagnosed diabetes (6.5% or higher). Consistently high or low levels can guide treatment adjustments, such as medication changes or lifestyle recommendations.
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