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

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

This test measures your average blood sugar levels over the past 2 to 3 months, helping your healthcare provider understand how well your diabetes is controlled.

Quick summary

["HbA1c reflects your long-term blood sugar management and is key to diabetes care."]

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

Key facts at a glance

LOINC
7401-3
Short code
Herring IgG Qn
Synonyms
Herring IgG Qn
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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

Why HbA1c Matters in Diabetes Management

HbA1c provides a snapshot of your blood sugar control over time, which can help prevent complications like nerve damage, kidney disease, or vision problems. Unlike daily blood sugar checks, it gives a broader picture of trends in your health.

How HbA1c Is Measured

This test uses a specialized blood sample collected from your vein. The blood is processed through a high-performance liquid chromatography (HPLC) machine, which separates hemoglobin molecules based on their A1c content. The machine then calculates your HbA1c percentage.

What Normal HbA1c Levels Indicate

While reference ranges can vary slightly by lab, an HbA1c level below 5.7% is generally considered normal for people without diabetes. For those with diabetes, a target range is typically 7.0% or lower, but this can be adjusted based on individual health needs and goals.

What HbA1c Levels Mean for Your Health

An HbA1c level above 7.0% may indicate poor blood sugar control and could increase the risk of diabetes-related complications. Levels below 6.5% might suggest you’re managing blood sugar too aggressively, which can also have risks.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: HbA1c in Diabetes and Beyond

Short name

HbA1c

Frequently asked questions

How often should I get an HbA1c test?
If you have diabetes, your healthcare provider will likely recommend an HbA1c test every 3 to 6 months to monitor your blood sugar control. If you’re at risk for diabetes (e.g., due to family history or obesity), you may need screening more frequently, often starting at age 45 or earlier.
What does an abnormal HbA1c result mean?
An abnormal HbA1c result means your blood sugar levels have been consistently higher or lower than what’s considered healthy over time. This doesn’t mean your current blood sugar is abnormal—it’s about your long-term average. Your provider will discuss lifestyle changes, medications, or further testing to help you manage it.
Can HbA1c be affected by things other than diabetes?
Yes, factors like anemia, kidney disease, certain medications (e.g., some blood pressure drugs), or pregnancy can affect HbA1c levels. If your results seem unusual, your provider may order additional tests to check for these influences.
  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