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Hemoglobin A1c (HbA1c) measured 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 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
716-1
Short code
Heinz Bod Bld Ql Smear
Synonyms
Heinz Bod Bld Ql Smear
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
microscopy-light
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 HbA1c Matters

HbA1c is a key indicator of how well your blood sugar has been controlled over time. Unlike daily blood sugar checks, it provides a broader picture of your health, especially useful for managing conditions like diabetes.

How It Works

Blood is drawn and processed to separate hemoglobin from other blood components. The test then analyzes the sugar (glycated) attached to the hemoglobin molecules using HPLC, a precise method that separates and measures these components.

What It Measures

HbA1c reflects the percentage of hemoglobin molecules that have sugar molecules attached. This percentage is directly tied to your average blood sugar levels during the previous 2–3 months, as sugar attaches to hemoglobin over time.

When to Get It

HbA1c is typically ordered every 3–6 months for people with diabetes to monitor progress with treatment. It may also be used for screening in high-risk individuals or during pregnancy.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

HbA1c

Frequently asked questions

HbA1c is a powerful tool for diagnosing diabetes (when levels are consistently above 6.5%) and assessing long-term diabetes management. Lower levels suggest better control, while higher levels indicate poorer management and potential complications.
HbA1c results are expressed as a percentage and are compared to standard reference ranges to determine if your blood sugar levels are within target ranges for your condition.
What does an abnormal HbA1c result mean?
An abnormal HbA1c result may indicate poor blood sugar control, which can increase the risk of diabetes-related complications like nerve damage, kidney problems, or heart disease. Your healthcare provider will discuss next steps, such as adjusting medications or lifestyle changes.
Can HbA1c be affected by other factors?
Yes, factors like smoking, certain medications (e.g., iron supplements), or blood loss can temporarily affect HbA1c results. If you suspect these factors may influence your test, discuss them with your doctor before your appointment.
  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