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Hemoglobin A1c (HbA1c) with Fluorescence Immunoassay (FIA) in Whole Blood

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

This test measures the average level of blood sugar (glucose) over the past 2–3 months by checking the percentage of hemoglobin molecules coated with glucose.

Quick summary

["Helps 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
93397-8
Short code
Haem influ DNA Bld Pos Ql NAA+probe
Synonyms
Haem influ DNA Bld Pos Ql NAA+probe
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Matters for You

Unlike a single blood sugar check, HbA1c gives a clearer picture of how well your body manages glucose over time. It’s especially useful for people with diabetes to adjust treatment plans and avoid complications like nerve damage or heart disease.

How the Test Works

A small blood sample is taken from your arm. The test uses fluorescence to detect glucose attached to hemoglobin, providing a stable measure regardless of recent blood sugar fluctuations.

What to Expect Before the Test

No special preparation is needed. You may eat or drink normally before the test, but fasting isn’t required. If you’re on insulin or diabetes medications, let your provider know.

What the Results Mean

Results are expressed as a percentage (e.g., 6.5%). Higher percentages indicate poorer long-term glucose control. Your provider will interpret results in the context of your overall health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: HbA1c in Diabetes Care

Short name

HbA1c (FIA)

Frequently asked questions

HbA1c is a gold standard for monitoring diabetes because it reflects average blood sugar levels over months. It helps identify trends, assess treatment effectiveness, and reduce risks of diabetes-related complications.
This test is not affected by short-term stress, illness, or recent meals, making it more reliable than daily blood sugar checks alone.
How often should I get this test?
Typically, people with diabetes get HbA1c tested every 2–3 months. Your provider may adjust frequency based on your treatment goals and blood sugar trends.
What if my HbA1c is higher than expected?
A higher HbA1c suggests your blood sugar may be consistently elevated. Your provider will work with you to adjust diet, exercise, or medications to improve control.
  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