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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 levels over the past 2–3 months by examining your red blood cells. It helps doctors assess long-term control of diabetes or prediabetes.

Quick summary

["HbA1c reflects your blood sugar trends over time, aiding diabetes management."]

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

Key facts at a glance

LOINC
53957-7
Short code
HCG-TM SerPl-mCnc
Synonyms
HCG-TM SerPl-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
0
Ref high
5
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
84702
SNOMED
275917004
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 HbA1c Matters

Unlike daily blood sugar checks, HbA1c gives a broader picture of how well your body manages glucose. It’s a key tool for doctors to adjust treatments like insulin or diet plans.

How It Works

Your blood sample is analyzed using HPLC, which separates hemoglobin types based on their sugar attachment. The test detects the percentage of hemoglobin bound to glucose (HbA1c).

Sample Preparation

A simple blood draw from your arm provides the sample. No special preparation is needed, but fasting isn’t required for this test.

What It Indicates

Higher HbA1c levels suggest poorer blood sugar control, while lower levels may indicate better management. It’s not a one-time check but part of ongoing diabetes care.

Reference range

Non-pregnant: <5 mIU/mLN/A

Specimen: serum

No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HbA1c

Frequently asked questions

What causes HbA1c to change?
Several factors influence HbA1c, including diet, exercise, medications (like insulin), illness, stress, or recent blood sugar spikes or drops. It reflects long-term trends, not immediate changes.
Does HbA1c change with age?
Yes, HbA1c levels can slightly increase with age due to changes in red blood cell lifespan. However, this is usually minimal unless underlying health conditions (like kidney disease) affect it.
Can lifestyle changes affect HbA1c results?
Absolutely. Improving diet, increasing physical activity, or quitting smoking can lower HbA1c over time. Conversely, poor diet, inactivity, or illness may raise it, so consistent monitoring helps track progress.
  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