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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 blood sugar (glucose) levels over the past 2–3 months by analyzing your red blood cells.

Quick summary

["Helps 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
54059-1
Short code
HEDIS 2009 PPC-C
Synonyms
HEDIS 2009 PPC-C
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 It Matters for Diabetes Management

HbA1c reflects your blood sugar levels over time, offering a snapshot of how well your diabetes has been managed. Unlike daily blood glucose checks, this test provides a broader perspective, helping healthcare providers assess trends and make informed decisions about your care.

How the Test Works

Your blood sample is analyzed using high-performance liquid chromatography (HPLC), a precise method that separates hemoglobin molecules based on their sugar content. The test identifies the proportion of hemoglobin bound to glucose (HbA1c) and converts this into a percentage.

What to Expect Before the Test

No special preparation is needed. A healthcare professional will draw blood from a vein in your arm. The process is quick and typically painless, with minimal discomfort. If you’re on blood thinners, let your provider know before the test.

Possible Results and Interpretation

Results are expressed as a percentage. While exact reference ranges vary by lab, values are generally interpreted as follows: below 5.7% is considered normal; 5.7%–6.4% indicates prediabetes; 6.5% or higher suggests diabetes. Your results will be discussed with your doctor to guide next steps.

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 this test?
Typically, people with diabetes are advised to check their HbA1c every 3–6 months to monitor progress and adjust medications or lifestyle changes as needed. Your doctor may recommend more frequent testing if you’re managing complex conditions or have rapid changes in blood sugar.
Can diet or exercise affect my HbA1c results?
Yes, both diet and exercise can influence your HbA1c levels. Eating a balanced diet rich in fiber and reducing sugary foods can help lower blood sugar, while regular physical activity improves insulin sensitivity. Small, gradual lifestyle changes often yield the best long-term results.
What if my HbA1c is higher than expected?
If your HbA1c is elevated, your doctor may recommend lifestyle modifications, such as improved meal planning, increased physical activity, or adjustments to your diabetes medications. They may also suggest additional tests or referrals to a dietitian or endocrinologist for personalized guidance.
  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