Hemoglobin A1c (HbA1c) with mass concentration measurement from whole blood
This test measures the average level of hemoglobin A1c in your blood over the past 2–3 months, reflecting your long-term blood sugar control.
["HbA1c helps doctors assess how well your diabetes is managed over time."]
Key facts at a glance
- LOINC
- 71861-9
- Short code
- Hgb Lepore MFr.DF Bld
- Synonyms
- Hgb Lepore MFr.DF 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
What HbA1c Measures
HbA1c is a form of hemoglobin (the protein in red blood cells that carries oxygen) that has been attached to sugar (glucose) from your blood. This test quantifies the percentage of hemoglobin A1c in your blood, giving a snapshot of your average blood sugar levels over time.
Why It’s Used
HbA1c is a key tool for diagnosing diabetes and monitoring treatment effectiveness. It’s particularly useful because it accounts for fluctuations in blood sugar that daily measurements might miss.
How It Works
Blood is drawn from a vein, typically in your arm. The sample is analyzed to determine the proportion of hemoglobin A1c relative to total hemoglobin, usually expressed as a percentage.
What to Expect Before the Test
No special preparation is needed, but you may be asked to fast for 8–12 hours if your doctor specifies it for other tests. Wear comfortable clothing and bring any medications you’re currently taking.
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 levels help identify diabetes (typically ≥6.5%) or prediabetes (4.0–5.7%). Lower-than-normal levels may suggest effective glucose control, while higher levels indicate poor management and potential complications like nerve damage or kidney disease.
Short name
HbA1c
Frequently asked questions
How often should I get this test?
What does an abnormal HbA1c result mean?
Can diet or exercise 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