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Hemoglobin A1c (Glycated Hemoglobin) measured by high-performance liquid chromatography (HPLC)

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

This test measures the percentage of hemoglobin in your blood that has sugar (glucose) attached to it. It reflects your average blood sugar levels over the past 2–3 months.

Quick summary

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

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

Key facts at a glance

LOINC
111469-3
Short code
HCV RNA Msmt SerPl
Synonyms
HCV RNA Msmt SerPl
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
86803
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

Why This Test Matters for You

HbA1c is a key indicator of how well your diabetes is managed over time. Unlike daily blood sugar checks, it provides a broader picture of your average glucose levels, helping prevent complications like nerve damage or kidney disease.

How the Test Works

Blood is drawn from your arm and sent to a lab where high-performance liquid chromatography separates hemoglobin types. The machine then measures the proportion of hemoglobin with attached glucose, expressed as a percentage.

What to Expect Before the Test

No special preparation is needed. You may eat and drink normally, but fasting is not required. Wear comfortable clothing and bring any medications you’re currently taking.

What to Expect During the Test

A healthcare provider will insert a small needle into your arm to draw a blood sample. The process is quick and typically causes minimal discomfort. You may feel a slight pinch or sting.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HbA1c

Frequently asked questions

HbA1c is crucial for diagnosing diabetes, monitoring treatment effectiveness, and identifying risks for complications. Values above or below typical ranges may signal poor or improved control, prompting adjustments to diet, exercise, or medication.
HbA1c results are interpreted in the context of your overall health, symptoms, and treatment plan. A doctor will explain what your result means for you personally.
How often should I get this test?
For most people with diabetes, HbA1c testing is recommended every 3–6 months. Your doctor may adjust this frequency based on your blood sugar goals and how well your treatment is working.
What does an abnormal HbA1c result mean?
An HbA1c result above 7% (varies by lab) may indicate poor blood sugar control and could increase your risk of diabetes-related complications. A result below 6% may suggest you’re managing blood sugar too aggressively, which could cause side effects from medications.
  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