Skip to content

Hemoglobin A1c (HbA1c) by High-Performance Liquid Chromatography (HPLC)

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

["HbA1c helps doctors track diabetes management and long-term blood sugar control."]

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

Key facts at a glance

LOINC
55241-4
Short code
HBB c.19G>A Bld Ql
Synonyms
HBB c.19G>A 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 tool for managing diabetes because it gives a snapshot of how well your blood sugar has been controlled over time, rather than just a single moment’s reading. Unlike fasting glucose tests, it accounts for fluctuations in your daily routine.

How It Works

Blood is drawn and processed to separate hemoglobin from other blood components. High-performance liquid chromatography (HPLC) then separates the different types of hemoglobin, including the sugar-coated HbA1c, which is measured as a percentage of total hemoglobin.

What to Expect

You’ll receive a small tube of blood, typically drawn from your arm. The test is usually done in a lab and results are ready within a few days. No special preparation is needed, but fasting isn’t required.

Common Reasons for Testing

Doctors order HbA1c tests to diagnose diabetes, monitor existing diabetes, or check for prediabetes. It’s also used to assess how well treatments like medication or diet are working over time.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HbA1c

Frequently asked questions

What does an abnormal HbA1c result mean?
An HbA1c result above the typical range (usually 4–6%) suggests poor blood sugar control and may indicate diabetes or prediabetes. A result below the reference range might raise questions about underlying conditions like iron deficiency or other metabolic issues.
How often should I get this test?
For people with diabetes, HbA1c testing is often recommended every 3–6 months to track progress. Your doctor will determine how frequently you need testing based on your health status and treatment plan.
Can lifestyle changes affect HbA1c results?
Yes! Improving diet, increasing physical activity, or adjusting medications can lower HbA1c levels over time. Small, consistent changes often lead to better long-term results.
  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