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Hemoglobin A1c (HbA1c) measured by high-performance liquid chromatography (HPLC)

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

This test measures your average blood sugar levels over the past 2–3 months, helping doctors assess long-term diabetes control.

Quick summary

["HbA1c reflects your blood sugar management over time, a key measure for diabetes care."]

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

Key facts at a glance

LOINC
41433-4
Short code
C hominis DNA Spec Ql NAA+probe
Synonyms
C hominis DNA Spec Ql NAA+probe
Category
coagulation
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
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 standard test for diagnosing diabetes and monitoring treatment effectiveness.

How It’s Done

A small blood sample is taken from your arm, usually during a routine visit. The sample is processed using HPLC to measure the percentage of hemoglobin bound to sugar.

What the Results Mean

Results are typically reported as a percentage. While exact ranges vary by lab, higher levels may indicate poor glucose control, while lower levels may suggest better management.

Common Reasons for Testing

Doctors order HbA1c to diagnose diabetes, check for prediabetes, or evaluate how well diabetes medications or lifestyle changes are working.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HbA1c

Frequently asked questions

What does an abnormal HbA1c result mean?
An abnormal result may signal poor blood sugar control, which could require adjustments to diet, exercise, or medication. Follow-up with your healthcare provider is important to discuss next steps.
Can HbA1c be affected by other health conditions?
Yes, conditions like anemia, kidney disease, or certain medications can influence HbA1c levels. Your doctor may order additional tests to rule out these factors if needed.
How often should I get an HbA1c test?
Typically, people with diabetes check their HbA1c every 3–6 months to monitor progress. Your doctor will recommend a schedule based on your specific needs.
  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