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Hemoglobin A1c (HbA1c) concentration

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

This test measures the average level of hemoglobin A1c in your blood over the past 2–3 months, reflecting your long-term blood sugar control.

Quick summary

["HbA1c helps doctors assess how well your diabetes is managed over time."]

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

Key facts at a glance

LOINC
12715-9
Short code
HVA Ur-mRate
Synonyms
HVA Ur-mRate
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What Is HbA1c Used For?

HbA1c is primarily used to diagnose diabetes, monitor treatment effectiveness, and adjust medication if needed. It provides a snapshot of your blood sugar levels over time, which can help prevent complications like nerve damage or kidney disease.

How Is HbA1c Tested?

The test uses a small blood sample (usually from your finger) and measures the percentage of hemoglobin molecules that are bound to glucose. This is done through an immunoassay method, often a type of chemiluminescent immunoassay (CLIA).

Why Is HbA1c Important?

Unlike daily blood sugar checks, HbA1c gives a broader picture of your average blood sugar levels, helping doctors identify trends and make informed decisions about your care plan.

What Does a Low or High HbA1c Mean?

A low HbA1c may indicate poor blood sugar control, while a high HbA1c suggests consistently elevated blood sugar levels, which can increase diabetes-related risks. Your results will be interpreted by your healthcare provider in the context of your overall health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HbA1c

Frequently asked questions

What causes HbA1c levels to change?
HbA1c levels can fluctuate due to changes in diet, physical activity, illness, stress, or medication. If you’ve had recent blood transfusions, your HbA1c may not reflect your current blood sugar levels accurately.
How often should I get an HbA1c test?
Your healthcare provider will determine how often you need testing based on your diabetes management plan. Typically, people with diabetes are tested every 3–6 months to monitor progress and adjust treatment as needed.
Can lifestyle changes affect HbA1c results?
Yes! Improving diet, increasing physical activity, and managing stress can help lower HbA1c levels over time. However, results may take weeks or months to reflect these changes, so consistency is key.
  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