Glucose, 24-Hour Average Concentration (from Hemoglobin Glycation)
This test measures the average blood sugar levels over the past 2–3 months by analyzing a protein in your red blood cells called hemoglobin. It reflects how well your body manages glucose over time.
["Helps track long-term blood sugar control, useful for diabetes management."]
Key facts at a glance
- LOINC
- 49134-0
- Short code
- Glucose 2h p Glc Bld-mCnc
- Synonyms
- Glucose 2h p Glc Bld-mCnc
- Category
- glucose
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 70
- Ref high
- 100
- Critical range
- 50 N/A – 400 N/A
- Fasting
- true
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82947
- SNOMED
- 260395008
- 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
Why This Test Matters for You
Unlike a single blood sugar check, this test gives a snapshot of your glucose levels over a longer period. It’s particularly useful for people with diabetes to assess how well their treatment plan is working over time.
How It’s Done
A small blood sample is taken from your arm. The hemoglobin in your red blood cells is analyzed to determine how much glucose has been attached to it over time. This process doesn’t require fasting.
What to Expect Before or After
No special preparation is needed. You may feel slight discomfort from the needle, but it’s usually over quickly. Results can take a few days to arrive, depending on your lab.
Common Reasons for This Test
Doctors order this test to monitor diabetes control, check for undiagnosed diabetes, or evaluate how well medications are working. It’s also useful for people with kidney disease or other conditions that affect blood sugar.
Reference range
Fasting: 70-100 mg/dLN/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.
HbA1c levels above 6.5% on two separate tests typically indicate diabetes. Lower levels (below 5.7%) suggest good blood sugar control, while levels between 5.7% and 6.4% may indicate prediabetes. This test helps identify trends over time and adjusts treatment plans accordingly.
Short name
HbA1c (24h avg glucose)
Frequently asked questions
What does an HbA1c result of 6.2% mean?
How often should I get this test?
Can diet or exercise affect my 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