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Hemoglobin A1c (HbA1c) with High-Performance Liquid Chromatography (HPLC) Method

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

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

Quick summary

["HbA1c helps doctors 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
31771-9
Short code
C trach Ag Cvx Ql
Synonyms
C trach Ag Cvx Ql
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 Is HbA1c Used For?

HbA1c is primarily used to diagnose type 1 and type 2 diabetes and assess how well blood sugar is controlled over time. It’s a key tool for long-term monitoring, especially in people with diabetes, to prevent complications like nerve damage or kidney disease.

How Is HbA1c Different from Fasting Blood Sugar?

Unlike a single blood sugar test (e.g., fasting glucose), HbA1c gives a broader picture of average glucose levels, accounting for daily fluctuations. It’s less affected by short-term stress or meals but requires consistent blood collection over time.

How Often Should HbA1c Be Checked?

Healthcare providers typically recommend HbA1c testing every 3–6 months for people with diabetes to adjust treatment plans. Others without diabetes may get baseline tests if at risk (e.g., obesity, family history).

What Does a High or Low HbA1c Mean?

A higher HbA1c (typically ≥6.5%) suggests poor blood sugar control and may indicate diabetes or prediabetes. A lower value (below 5.7%) often means good control, but results depend on your health status and treatment.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HbA1c

Frequently asked questions

Why do doctors use HbA1c instead of checking blood sugar daily?
Daily blood sugar checks can be inconsistent due to lifestyle factors. HbA1c provides a stable, objective measure of long-term glucose exposure, helping doctors set realistic goals and adjust medications like insulin or metformin.
Can HbA1c be affected by other health conditions?
Yes, conditions like anemia, kidney disease, or certain medications (e.g., blood thinners) can alter HbA1c results. Always discuss your test with your doctor if you suspect these factors may apply.
How long does it take to get HbA1c results?
Results are usually available within 1–3 business days, depending on your lab. Some clinics offer same-day or next-day reporting for urgent cases.
  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