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Hemoglobin A1c (HbA1c) with Immunoassay Method

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

This test measures the average blood sugar level over the past 2–3 months by checking the percentage of hemoglobin (red blood cell protein) that is bonded to sugar.

Quick summary

["Helps doctors track long-term blood sugar control for diabetes management."]

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

Key facts at a glance

LOINC
104412-2
Short code
HAV IgM Titr Ser
Synonyms
HAV IgM Titr Ser
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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

What Does This Test Measure?

HbA1c reflects your blood sugar levels over time because hemoglobin stays in red blood cells for about 120 days. It’s a key indicator of how well your diabetes is managed over months, not just recent spikes or drops.

Why Is This Test Important?

Regular HbA1c testing helps prevent complications like nerve damage, kidney disease, or heart problems by ensuring consistent blood sugar control.

How Is This Test Done?

A small blood sample is taken from your arm, usually from a vein. The sample is sent to a lab where an immunoassay detects the hemoglobin molecules bonded to sugar.

What Are Common Results?

Results are reported as a percentage (e.g., 5.7%, 6.5%, 7.8%). Lower percentages (closer to 5.7%) suggest better control, while higher values indicate poorer management.

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 HbA1c above 6.5% typically confirms diabetes. Values between 5.7% and 6.4% may indicate prediabetes, prompting lifestyle or medical interventions.
How Often Should I Get This Test?
Doctors usually recommend testing every 3–6 months for people with diabetes to monitor progress and adjust care plans.
Can Diet or Exercise Affect HbA1c Results?
Yes—diet, exercise, and medications directly impact blood sugar levels, which influence HbA1c. Small, consistent changes (like reducing sugar intake or increasing activity) can improve results over time.
  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