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Hemoglobin A1c (HbA1c) with Immunoassay Method

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

This test measures the percentage of hemoglobin in your blood that is coated with sugar (glycated hemoglobin), reflecting your average blood sugar levels over the past 2–3 months.

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
77746-6
Short code
HTLV I gp46-I Ab SerPl Ql IB
Synonyms
HTLV I gp46-I Ab SerPl Ql IB
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ib
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 how your blood sugar levels have been managed over time by binding to hemoglobin, a protein in red blood cells. It’s a key indicator of whether your diabetes treatment is working effectively.

Why Is This Test Important?

Unlike daily blood sugar checks, HbA1c provides a broader picture of your glucose control, helping prevent complications like nerve damage or kidney disease.

How Is This Test Performed?

A small blood sample is taken from your arm, typically from a vein. The sample is processed to measure the percentage of glycated hemoglobin using an immunoassay method.

What Are Common Results?

Results are reported as a percentage (e.g., 5.7%–6.4% may indicate prediabetes or poor control). Exact ranges depend on your health status and doctor’s guidance.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: HbA1c is a gold-standard marker for diabetes diagnosis and monitoring. Values above 6.5% often confirm diabetes, while lower values may suggest effective treatment or prediabetes. Regular monitoring helps adjust medications or lifestyle changes to improve outcomes.

Short name

HbA1c

Frequently asked questions

How often should I get this test?
Typically, people with diabetes get HbA1c tested every 2–3 months to track progress. Your doctor will determine the best schedule for you based on your treatment plan.
Does diet or exercise affect HbA1c results?
Yes! Improving diet, increasing physical activity, or managing stress can lower HbA1c levels over time. Small, consistent changes often show gradual improvements.
Can fasting affect HbA1c results?
No, HbA1c measures average blood sugar over months, so fasting status doesn’t influence it. Unlike glucose tests, it doesn’t depend on when you last ate.
  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