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Hemoglobin A1c (HbA1c) with serum/plasma concentration measurement

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 blood sugar control during that time.

Quick summary

["HbA1c helps doctors track long-term diabetes management and adjust treatment plans."]

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

Key facts at a glance

LOINC
5200-1
Short code
HDV Ab Ser IA-aCnc
Synonyms
HDV Ab Ser IA-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
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 HbA1c Measures

HbA1c represents the percentage of hemoglobin molecules that are coated with sugar (glycated). It reflects how consistently your blood sugar levels have been within or outside the healthy range over time. This test is a key indicator of diabetes control and helps prevent complications by identifying trends in blood sugar management.

Why It’s Done

Your healthcare provider may order this test if you have diabetes, prediabetes, or are at risk for diabetes. It’s also used to monitor treatment effectiveness, assess long-term blood sugar trends, and detect undiagnosed diabetes in certain populations.

How It Works

Blood is drawn, and the serum or plasma is analyzed to measure the proportion of hemoglobin molecules bound to glucose. The test uses immunoassay or related methods to quantify this glycated hemoglobin percentage.

What to Expect

A simple blood draw is performed, usually from a vein in your arm. The test is quick and requires no special preparation, though fasting is not required. Results are typically available within a few days.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HbA1c

Frequently asked questions

How does HbA1c differ from my recent blood sugar readings?
HbA1c provides a broader picture of your blood sugar control over months, while recent blood sugar tests (like fasting glucose or random glucose) show short-term levels. HbA1c is less affected by acute fluctuations but reflects long-term trends.
What does my HbA1c result mean?
Results below 5.7% may indicate normal blood sugar, 5.7–6.4% suggests prediabetes, and 6.5% or higher typically confirms diabetes. Your doctor will interpret results in context with your medical history and symptoms.
Can HbA1c be affected by other conditions?
Yes, conditions like anemia, kidney disease, or certain medications (e.g., some blood thinners) may influence HbA1c levels. Your doctor will consider these factors when reviewing your results.
  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