Hemoglobin A1c (HbA1c) with High-Performance Liquid Chromatography (HPLC) method
This test measures the percentage of hemoglobin in your blood that is attached to sugar (glucose). It reflects your average blood sugar levels over the past 2–3 months.
["HbA1c helps doctors track long-term diabetes control and assess risk for complications."]
Key facts at a glance
- LOINC
- 23339-5
- Short code
- MAP Wheal 3D p .1mL Av PPD Diam
- Synonyms
- MAP Wheal 3D p .1mL Av PPD Diam
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- 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 HbA1c Measures
HbA1c is a stable form of hemoglobin that forms when glucose binds to the hemoglobin protein in red blood cells. It’s a key marker for chronic blood sugar levels, not just recent spikes. This test doesn’t measure *current* glucose but provides a snapshot of how well your body manages glucose over time.
Why It’s Done
Doctors order HbA1c to diagnose diabetes, monitor treatment progress, or detect prediabetes. It’s especially useful for people with type 1 or type 2 diabetes, as it helps adjust medications or lifestyle strategies.
How It Works
Blood is drawn and processed to separate red blood cells. The hemoglobin is then separated into its components using HPLC, which identifies the percentage of HbA1c relative to total hemoglobin. This method is precise and avoids interference from recent meals or activity levels.
What to Expect
You’ll have a small needle inserted into your arm, and a small amount of blood is collected. Results are typically ready within 1–3 business days. Avoid eating or drinking anything except water for 4 hours before the test if instructed.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
HbA1c is critical for diagnosing diabetes (typically ≥6.5%) and prediabetes (≥5.7%). Lower levels (below 5.7%) suggest good glucose control, while higher levels may indicate poor management, increased risk of nerve/kidney damage, or complications like heart disease. It’s a non-invasive, reliable tool for long-term health tracking.
Short name
HbA1c
Frequently asked questions
How often should I get an HbA1c test?
Can I eat or drink before this test?
Does HbA1c change with exercise or diet?
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