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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 average blood sugar levels over the past 2 to 3 months by looking at the percentage of hemoglobin molecules that have sugar attached to them.

Quick summary

["HbA1c helps doctors 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
24748-6
Short code
MR Hrt
Synonyms
MR Hrt
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
mr
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 Is HbA1c Used For?

HbA1c is primarily used to diagnose diabetes, assess how well blood sugar is being controlled over time, and help adjust treatment plans. It’s a key tool for monitoring chronic conditions like diabetes mellitus, including type 1 and type 2 diabetes.

How Is HbA1c Different from Fasting Blood Sugar?

Unlike a single blood sugar test (e.g., fasting glucose), HbA1c gives a broader picture of your average blood sugar levels, accounting for daily fluctuations. It’s less affected by short-term stress or meals, making it a reliable indicator of long-term health.

How Is HbA1c Tested?

This test involves a simple blood draw from your arm. The blood is processed to separate hemoglobin and then analyzed using HPLC to measure the percentage of hemoglobin with attached sugar molecules.

What Does an HbA1c Result Mean?

Results are typically reported as a percentage (e.g., 5.7%, 6.5%, 7.0%). While specific ranges vary by lab, higher percentages generally indicate poorer blood sugar control, while lower percentages suggest better control. Your doctor will interpret results in the context of your overall health and treatment plan.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance of HbA1c

Short name

HbA1c

Frequently asked questions

Why might my doctor order an HbA1c test?
Your doctor may order this test if you have symptoms of diabetes (e.g., frequent urination, extreme thirst), a family history of diabetes, or if you’re at risk due to age, obesity, or other health conditions. It’s also used to monitor diabetes progression, evaluate treatment effectiveness, and prevent complications like nerve damage or heart disease.
How often should I get an HbA1c test?
If you have diabetes, your doctor may recommend testing every 3 to 6 months to track changes in your blood sugar control. If you’re pre-diabetic or at high risk, testing may be less frequent (e.g., annually). Follow your healthcare provider’s advice for timing and frequency.
Can lifestyle changes affect HbA1c results?
Yes! Making healthy choices like eating balanced meals, staying active, and managing stress can improve your HbA1c levels over time. Even small adjustments, such as reducing sugar intake or increasing physical activity, may lead to measurable improvements in your test 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