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

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

This test measures the average level of hemoglobin A1c in your blood over the past 2 to 3 months. Hemoglobin A1c reflects your blood sugar (glucose) levels during this time.

Quick summary

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

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

Key facts at a glance

LOINC
77482-8
Short code
Deprecated Hind+Mid ft-L XR 2V
Synonyms
Deprecated Hind+Mid ft-L XR 2V
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
xr
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 and monitor long-term blood sugar levels. It provides insight into whether your blood sugar has been consistently within a healthy range over time, which is important for managing conditions like diabetes.

How Is This Test Performed?

A small blood sample is taken from your arm. The blood is then processed and analyzed using high-performance liquid chromatography (HPLC) to measure the percentage of hemoglobin A1c in your red blood cells.

Why Is This Test Important?

Regular HbA1c testing helps healthcare providers assess whether your diabetes is well-controlled. It’s a key tool for preventing complications related to high blood sugar, such as nerve damage, kidney disease, or heart disease.

What Does an Abnormal HbA1c Result Mean?

Results above the typical reference range may indicate poor blood sugar control and could signal diabetes or pre-diabetes. Results below the range might suggest consistently low blood sugar, though this is less common and requires further evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

HbA1c results are clinically significant because they offer a broader picture of blood sugar management than a single blood glucose measurement. It’s a critical metric for long-term diabetes care and helps adjust treatment plans as needed.

Short name

HbA1c

Frequently asked questions

What causes high HbA1c levels?
High HbA1c levels are most commonly associated with diabetes, whether type 1 or type 2. Other factors, such as chronic kidney disease, certain medications, or severe infections, can also influence results.
How often should I get an HbA1c test?
For people with diabetes, HbA1c testing is typically recommended every 3 to 6 months. Your healthcare provider may adjust this frequency based on your specific needs and how well your diabetes is controlled.
Can lifestyle changes affect HbA1c results?
Yes, lifestyle changes such as diet, exercise, and managing stress can significantly impact HbA1c levels. Improving these habits often leads to better blood sugar control and lower HbA1c percentages.
  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