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Hemoglobin A1c (HbA1c) by Electrophoresis

Published: August 9, 2026Updated: August 16, 2026

This test measures the average level of hemoglobin A1c in your blood over the past 2–3 months, reflecting your blood sugar control during that time.

Quick summary

["HbA1c helps doctors assess long-term diabetes management and adjust treatment plans."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
71874-2
Short code
Hgb A2 MFr.DF Bld Elph
Synonyms
Hgb A2 MFr.DF Bld Elph
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
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 HbA1c Measures

HbA1c is a form of hemoglobin (the protein in red blood cells that carries oxygen) that has been linked to glucose (sugar) over time. It’s a stable marker that reflects your average blood sugar levels during the production cycle of red blood cells, which lasts about 120 days.

How It Works

This test uses electrophoresis to separate hemoglobin variants, including HbA1c, based on their electrical charge. The percentage of HbA1c is calculated from this separation.

Why It’s Important

Unlike checking blood sugar levels at a single time point, HbA1c provides a broader picture of how well your blood sugar has been controlled over months, which is critical for managing diabetes or prediabetes.

What to Expect

A blood sample is drawn from a vein in your arm. The process is quick and usually painless. The test result is typically reported as a percentage (e.g., 5.7%–6.4% is considered prediabetes, while 6.5% or higher may indicate diabetes).

Reference range

Adult males: 13.5-17.5 g/dL; Females: 12.0-16.0 g/dLN/A

Specimen: whole-blood

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.

◆Associated findings1

Short name

HbA1c

Frequently asked questions

How often should I get this test?
HbA1c is recommended at least twice a year for people with diabetes and annually for those at high risk of developing diabetes or with prediabetes. Your doctor may adjust frequency based on your health status and treatment goals.
Can lifestyle changes affect HbA1c results?
Yes, consistent lifestyle changes such as healthy eating, regular physical activity, and managing stress can improve HbA1c levels. However, results may take several weeks to reflect these changes, so it’s important to work with your healthcare team to track progress over time.
What does an abnormal HbA1c result mean?
An HbA1c result above 6.5% is diagnostic for diabetes. Levels between 5.7% and 6.4% indicate prediabetes, signaling a higher risk of developing diabetes. Your doctor will discuss next steps, such as dietary adjustments, exercise plans, or medication, based on your result.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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