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Glycated hemoglobin (HbA₁c) using high-performance liquid chromatography (HPLC) from whole blood

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

This test measures how much of your hemoglobin molecules are attached to sugar (glycated), reflecting your average blood sugar levels over the past 2–3 months.

Quick summary

["Helps track long-term blood sugar control for diabetes management."]

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

Key facts at a glance

LOINC
55249-7
Short code
HBA2 SEA Del Bld Ql
Synonyms
HBA2 SEA Del Bld Ql
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
molgen
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 This Test Matters

HbA₁c is a key marker for managing diabetes and prediabetes because it gives a snapshot of your blood sugar trends over time, unlike daily glucose checks. It’s less affected by short-term fluctuations (like meals or stress) than immediate blood sugar tests.

How It Works

Your blood sample is analyzed using high-performance liquid chromatography (HPLC), a precise method that separates and measures glycated hemoglobin levels. This avoids variability from other blood components.

What to Expect Before the Test

No special preparation is needed. You may fast for 8–12 hours before testing if instructed by your provider, but fasting is not required for this test. Bring your test results and current medications to your appointment.

What the Results Mean

Results are typically reported as a percentage. Higher levels may indicate poor blood sugar control, while lower levels may suggest consistently low blood sugar. Your doctor will interpret results in the context of your health and treatment plan.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: HbA₁c is critical for diagnosing diabetes, monitoring treatment effectiveness, and preventing complications like nerve damage or heart disease. It’s especially useful for patients with diabetes who may not feel symptoms of high blood sugar.

Short name

HbA₁c (Blood Sugar Control Test)

Frequently asked questions

What does an abnormal HbA₁c result mean?
An abnormal result (typically outside the 4–6% range for non-diabetics or higher for diabetics) may signal diabetes, prediabetes, or poor management of existing diabetes. Your doctor will discuss next steps, such as adjusting medications or lifestyle changes.
Can HbA₁c levels change quickly?
HbA₁c reflects long-term trends (2–3 months), so changes take time to develop. Short-term diet, exercise, or illness may temporarily affect daily blood sugar but won’t immediately alter HbA₁c results.
Is fasting required for this test?
No fasting is required unless your doctor specifies it. This test measures glycated hemoglobin regardless of when you last ate, making it ideal for routine monitoring.
  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