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Hemoglobin A1c (HbA1c) by Electrophoresis

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

This test measures the percentage of hemoglobin that is coated with sugar, reflecting your average blood sugar levels over the past 2–3 months.

Quick summary

["Helps doctors track long-term diabetes control and adjust treatment plans."]

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

Key facts at a glance

LOINC
4549-2
Short code
HbA1c MFr Bld Elph
Synonyms
HbA1c MFr Bld Elph
Category
hematology
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Ref low
4
Ref high
5.6
Critical range
2 N/A – 14 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
electrophoresis
CPT
83037
SNOMED
43387009
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 Does This Test Measure?

HbA1c reflects the amount of sugar (glucose) that has attached to hemoglobin, the protein in red blood cells that carries oxygen. This attachment is a stable marker of your blood sugar levels over time, not just recent spikes or drops.

Why Is This Test Important?

Unlike daily blood sugar checks, HbA1c gives a broader picture of how well your diabetes or prediabetes is managed, helping prevent complications like nerve damage or heart disease.

How Is the Sample Collected?

A small blood sample is taken from your arm, similar to a standard blood draw. The test uses electrophoresis to separate hemoglobin types, including HbA1c.

What Are Common Uses?

Doctors use HbA1c to diagnose diabetes, monitor treatment progress, and assess long-term blood sugar control in people with diabetes or prediabetes.

Reference range

Normal: 4.0-5.6%N/A

Specimen: whole-blood

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.

◆Associated findings1

Short name

HbA1c

Frequently asked questions

How often should I get this test?
Typically, adults with diabetes get HbA1c checked every 3–6 months to track progress. Your doctor may adjust frequency based on your treatment plan.
What do different HbA1c results mean?
Results are usually reported as a percentage (e.g., 5.7%–6.4% may indicate prediabetes; 6.5% or higher often confirms diabetes). Your doctor will interpret results in context with your health.
Can lifestyle changes affect HbA1c results?
Yes—diet, exercise, and managing stress can lower HbA1c. Small, consistent changes often show improvements over time, but results may take weeks to reflect.
  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