Hemoglobin A1c (HbA1c) by Electrophoresis on Whole Blood
This test measures the percentage of hemoglobin that is coated with sugar, reflecting your average blood sugar levels over the past 2–3 months.
["Helps track long-term diabetes management and glucose control."]
Key facts at a glance
- LOINC
- 4565-8
- Short code
- Hgb Chesap Bld Ql Elph Acid
- Synonyms
- Hgb Chesap Bld Ql Elph Acid
- 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
- Method
- electrophoresis-ph
- 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 Is HbA1c Used For?
HbA1c is primarily used to diagnose diabetes, assess how well your blood sugar is managed over time, and guide treatment decisions. It’s a key tool for people with diabetes to monitor their condition and adjust their care plan accordingly.
How Is This Test Performed?
A small blood sample is taken from your arm, typically during a routine visit to your healthcare provider. The blood is then analyzed using electrophoresis, a method that separates hemoglobin types based on their electrical charge.
Why Is HbA1c Important?
Unlike daily blood sugar checks, HbA1c gives a broader picture of your blood sugar trends, helping prevent complications like nerve damage, kidney disease, or vision problems. It’s a reliable indicator of how well your body handles glucose over time.
What Does a High or Low HbA1c Mean?
A higher HbA1c level (typically above 6.5%) suggests poor blood sugar control and may indicate diabetes or prediabetes. A lower level (below 5.7%) may indicate excellent control, but this depends on your overall health and medical history.
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: HbA1c is a gold-standard marker for chronic hyperglycemia, used to diagnose diabetes (when ≥6.5%), screen for prediabetes (5.7–6.4%), and evaluate glycemic control in patients with diabetes. It reduces reliance on short-term glucose measurements and provides a more stable reflection of metabolic health.
Short name
HbA1c (Blood Sugar Control)
Frequently asked questions
How often should I get an HbA1c test?
Can HbA1c be affected by factors like iron deficiency or anemia?
Does 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