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Hemoglobin A1c (HbA1c) with high-performance liquid chromatography (HPLC) measurement

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

This test measures the average blood sugar level over the past 2–3 months by analyzing your red blood cells.

Quick summary

["HbA1c helps track diabetes management and long-term blood sugar control."]

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

Key facts at a glance

LOINC
77483-6
Short code
Deprecated Hind+Mid ft-R XR 2V
Synonyms
Deprecated Hind+Mid ft-R 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

Why HbA1c Matters

Unlike daily blood sugar checks, HbA1c gives a broader picture of how well your body manages glucose over time. It reflects your average blood sugar levels from the production of new red blood cells, which live for about 3 months.

How It’s Done

A small blood sample is taken from your arm, usually during a routine visit. The sample is processed using high-performance liquid chromatography (HPLC) to measure the percentage of hemoglobin bound to glucose.

What the Results Mean

Results are typically reported as a percentage. While exact reference ranges vary by lab, higher levels often indicate poorer blood sugar control, which can be linked to diabetes or prediabetes. Your doctor will interpret results in the context of your overall health.

Clinical Significance

HbA1c is a key tool for diagnosing diabetes, monitoring treatment effectiveness, and preventing complications like nerve damage or kidney disease. Regular testing helps adjust medications or lifestyle changes as needed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

HbA1c is a widely used marker for assessing long-term glucose control in people with diabetes or those at risk. It’s less affected by short-term fluctuations in blood sugar compared to daily measurements, making it a reliable indicator of chronic management.

Short name

HbA1c

Frequently asked questions

How often should I get an HbA1c test?
If you have diabetes, your doctor may recommend testing every 3–6 months. For prediabetes or those at higher risk, testing may be done less frequently, such as once a year, unless advised otherwise.
Can HbA1c results change if I’ve had recent blood sugar changes?
Yes, HbA1c reflects average blood sugar levels over months, so recent spikes or drops (like from illness or medication) won’t immediately affect the result. It stabilizes as new red blood cells develop.
What if my HbA1c is higher than expected?
A higher HbA1c may signal poor blood sugar control. Your doctor could recommend lifestyle adjustments (like diet or exercise), medication changes, or further testing to identify underlying causes.
  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