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Hemoglobin A1c (HbA1c) with probe-based measurement in serum/plasma

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

This test measures the average blood sugar level over the past 2–3 months by examining 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
82169-4
Short code
FLUAV H3 RNA Nph Ql NAA+n-prb
Synonyms
FLUAV H3 RNA Nph Ql NAA+n-prb
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
non-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

What This Test Measures

HbA1c reflects the percentage of hemoglobin molecules coated with glucose, providing a snapshot of your blood sugar trends over time. It’s not affected by short-term fluctuations like meals or stress.

How It’s Used in Care

Doctors use HbA1c to diagnose diabetes, monitor treatment progress, and adjust medications if needed. A result helps identify whether your blood sugar is consistently within healthy or high-risk ranges.

Why It Matters for Health

Chronically high HbA1c levels correlate with increased risks of complications like nerve damage, kidney disease, or heart problems. Regular monitoring helps prevent these risks.

How the Test Works

A small blood sample is drawn, and the probe measures the stable bond between hemoglobin and glucose, yielding a percentage value.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: HbA1c is a gold-standard marker for glycemic control. Values below 5.7% are typically considered normal, while 5.7%–6.4% may indicate prediabetes, and 6.5% or higher suggests diabetes. It’s less influenced by daily activities than immediate blood sugar checks.

Short name

HbA1c

Frequently asked questions

Why might my HbA1c test be done?
Your doctor may order this test if you have diabetes, prediabetes, or if you’re at risk for diabetes due to factors like obesity, family history, or high blood pressure.
What do my results mean?
Results are usually reported as a percentage. For example, 6.5% means your blood sugar was higher than average over the past few months. Your doctor will interpret results in the context of your overall health.
Can lifestyle changes affect HbA1c?
Yes! Diet, exercise, and medications can lower HbA1c. Small, consistent changes—like eating balanced meals or walking daily—can improve long-term blood sugar 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