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Hemoglobin A1c (HbA1c) 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 diabetes control and long-term blood sugar health."]

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

Key facts at a glance

LOINC
26028-1
Short code
HLA-B27 Ql FC
Synonyms
HLA-B27 Ql FC
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
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 Measures

HbA1c reflects how well your blood sugar has been managed over time. It’s a stable form of hemoglobin that gets attached to glucose (sugar) in your red blood cells. This test is particularly useful for people with diabetes or those at risk for it.

Why It’s Done

Doctors order HbA1c to monitor diabetes treatment, assess long-term blood sugar trends, and prevent complications like nerve damage or kidney disease. It’s often checked every 3–6 months for people with diabetes.

How It’s Performed

A small blood sample is taken from your arm, usually via a needle. The sample is then processed using HPLC to separate hemoglobin types and measure the HbA1c percentage.

What the Results Mean

Results are typically reported as a percentage (e.g., 5.7%–6.4% is considered prediabetes; 6.5% or higher may indicate diabetes). Exact ranges can vary by lab, so discuss your results with your healthcare provider.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HbA1c

Frequently asked questions

How often should I get an HbA1c test?
For people without diabetes, an HbA1c test isn’t routinely recommended unless you have risk factors like obesity, a family history of diabetes, or high blood pressure. For diabetes patients, it’s usually checked every 2–3 months to adjust treatment as needed.
Can HbA1c be affected by other conditions?
Yes, conditions like anemia, kidney disease, or certain medications (e.g., blood thinners) can affect HbA1c levels. If you suspect an issue, discuss it with your doctor before interpreting results.
What if my HbA1c is high?
A high HbA1c suggests poor blood sugar control. Your doctor may recommend lifestyle changes (diet, exercise), medication adjustments, or further testing to identify causes like insulin resistance or other health issues.
  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