Hemoglobin A1c (HbA1c) with High-Performance Liquid Chromatography (HPLC) measurement
This test measures the average level of blood sugar (glucose) over the past 2 to 3 months, helping doctors assess long-term blood sugar control.
["HbA1c reflects your blood sugar management over time and is used to diagnose and monitor diabetes."]
Key facts at a glance
- LOINC
- 71887-4
- Short code
- COHgb MFr.DF BldCoA
- Synonyms
- COHgb MFr.DF BldCoA
- 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
Why Is This Test Done?
Your doctor may order an HbA1c test to check if your blood sugar levels are consistently within a healthy range. It’s particularly useful for people with diabetes or prediabetes to track how well their treatment plan is working.
How Is the Test Performed?
A small blood sample is taken from your arm, usually by a healthcare professional. The sample is then analyzed using high-performance liquid chromatography (HPLC) to measure the percentage of hemoglobin that is coated with glucose.
What Do the Results Mean?
While specific reference ranges vary by lab, higher levels may indicate poor blood sugar control, while lower levels might suggest better management. Your doctor will interpret the results in the context of your overall health and treatment plan.
Common Reasons for Testing
HbA1c testing is often done during routine check-ups for people with diabetes, to screen for prediabetes, or to monitor treatment progress. It’s also used to diagnose diabetes if other tests are inconclusive.
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.
Clinical Significance
Short name
HbA1c
Frequently asked questions
HbA1c is a key indicator of long-term blood sugar control and helps doctors adjust treatment plans, such as medication or lifestyle changes, to improve health outcomes. It’s less affected by short-term fluctuations in blood sugar compared to immediate glucose tests.
What does an abnormal HbA1c result mean?
Can HbA1c be affected by other health conditions?
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