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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 assess long-term blood sugar control for diabetes or prediabetes."]

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

Key facts at a glance

LOINC
94539-4
Short code
HAV IgM + total Pnl SerPl
Synonyms
HAV IgM + total Pnl SerPl
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
44
Ref high
147
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
84075
SNOMED
27550007
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 This Test Matters

Unlike daily blood sugar checks, HbA1c gives a broader picture of how well your body manages glucose over time. It’s especially useful for people with diabetes to track progress with treatment.

How It Works

Blood is drawn and processed to separate hemoglobin from other blood components. HPLC separates hemoglobin types based on sugar attachment, then calculates the percentage of HbA1c.

What to Expect

A small needle is used to draw blood from your arm. The process is quick and usually painless. Results are ready within a few days.

Common Reasons for Testing

Doctors order HbA1c to diagnose diabetes, monitor treatment effectiveness, or check for prediabetes. It’s also used in routine care for people at higher risk.

Reference range

Adult: 44-147 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

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, adults with diabetes get HbA1c tested every 3–6 months. Your doctor may adjust frequency based on your treatment plan or stability.
What does a high HbA1c mean?
A high HbA1c (typically ≥7%) suggests poor blood sugar control and may indicate untreated diabetes or inadequate treatment. It doesn’t mean you had high blood sugar *at the time* of testing—it’s an average over months.
Can lifestyle changes lower HbA1c?
Yes! Consistent exercise, a balanced diet, and managing stress can improve HbA1c levels over time. Work with your healthcare team to create a personalized plan.
  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