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Hemoglobin A1c (HbA1c) with High-Performance Liquid Chromatography (HPLC) Method

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
13299-3
Short code
HLAB
Synonyms
—
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What HbA1c Test Measures

HbA1c measures the proportion of hemoglobin molecules that have sugar molecules attached. This attachment is a direct indicator of how consistently your blood sugar has been within a healthy range over time. Unlike blood sugar tests that show current levels, HbA1c provides a snapshot of your glucose control over months, making it useful for long-term diabetes management.

Why HbA1c Matters

Regular HbA1c testing is essential for people with diabetes to assess whether their treatment plan is effective. It also helps identify trends, such as periods of high or low blood sugar, which can inform adjustments to medication, diet, or lifestyle.

How the Test Works

The test uses a blood sample to separate hemoglobin into its components, including HbA1c. High-performance liquid chromatography (HPLC) then precisely measures the percentage of HbA1c relative to total hemoglobin. This method ensures accurate and reliable results.

Common Uses

HbA1c is primarily used to diagnose diabetes, monitor its progression, and evaluate treatment effectiveness. It’s also helpful for pre-diabetes screening and assessing risk for complications like nerve damage or kidney disease.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

HbA1c

Frequently asked questions

How often should I get an HbA1c test?
Typically, people with diabetes should get an HbA1c test every 3–6 months. Your doctor may recommend more frequent testing if your blood sugar levels are unstable or if you’re adjusting treatments. Regular monitoring helps catch issues early and keeps your treatment plan on track.
What does an abnormal HbA1c result mean?
An HbA1c result above 6.5% is diagnostic for diabetes. Results between 5.7% and 6.4% suggest prediabetes, meaning your blood sugar is higher than normal but not yet diabetic. A result below 5.7% indicates good blood sugar control and is typically considered normal.
Can lifestyle changes alone affect HbA1c results?
Yes, lifestyle changes such as improving diet, increasing physical activity, and managing stress can significantly lower HbA1c levels. Even small improvements in these areas may lead to noticeable changes in your test results over time, especially if you’re working toward prediabetes or early diabetes management.
  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