Hemoglobin A1c (HbA1c) measurement
This test measures the average level of hemoglobin A1c in your blood over the past 2 to 3 months, reflecting your blood sugar control during that time.
["HbA1c helps doctors assess how well your diabetes is managed over time."]
Key facts at a glance
- LOINC
- 43150-2
- Short code
- Hb A1c Measurement Device Pnl
- Synonyms
- Hb A1c Measurement Device Pnl
- Category
- glucose
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 4
- Ref high
- 5.6
- Critical range
- 2 N/A – 14 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 83037
- SNOMED
- 43387009
- 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 Does HbA1c Measure?
HbA1c is a form of hemoglobin (the protein in red blood cells that carries oxygen) that has attached a sugar molecule (glucose) from your blood. The percentage of HbA1c in your bloodstream indicates how much glucose has been present over time. This test is a key indicator of long-term blood sugar levels, particularly useful for people with diabetes or prediabetes.
Why Is HbA1c Important?
Unlike a single blood sugar reading, HbA1c provides a snapshot of your average blood sugar levels over several months. It helps doctors determine if your diabetes treatment plan is effective and adjusts care as needed to maintain healthy blood sugar levels.
How Is HbA1c Tested?
The test typically involves a simple blood draw from a vein in your arm. The blood sample is analyzed using an automated device to measure the percentage of HbA1c in your red blood cells. Results are usually available within a few days.
What Are Common HbA1c Levels?
While specific reference ranges can vary by lab, HbA1c levels are often categorized as follows: below 5.7% is generally considered normal for people without diabetes; 5.7% to 6.4% indicates prediabetes; and 6.5% or higher suggests diabetes.
Reference range
Normal: 4.0-5.6%N/A
Fasting for 8-12 hours required. Water is permitted. Avoid chewing gum and smoking before the test.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: HbA1c is a critical tool for diagnosing diabetes, monitoring treatment progress, and preventing complications like nerve damage, kidney disease, and cardiovascular issues. Regular monitoring helps ensure your blood sugar stays within a healthy range to reduce long-term risks.
Short name
HbA1c
Frequently asked questions
How often should I get an HbA1c test?
Can HbA1c levels change quickly?
What factors can affect HbA1c test 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