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Hemoglobin A1c (HbA1c) by High-Performance Liquid Chromatography (HPLC) in Serum

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 assess 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
85380-4
Short code
HIV IA algorithm interp SerPlBld-Imp
Synonyms
HIV IA algorithm interp SerPlBld-Imp
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
86701
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 Test Measures

HbA1c reflects the amount of glucose (sugar) that has attached to hemoglobin in red blood cells. It’s a key indicator of how well your blood sugar has been controlled over time, especially useful for people with diabetes or prediabetes.

Why It’s Done

Your doctor may order this test to monitor diabetes treatment effectiveness, diagnose diabetes, or check for complications like nerve damage or kidney issues linked to high blood sugar.

How It Works

A small blood sample is taken from your arm and sent to a lab. HPLC separates hemoglobin types based on sugar attachment, then calculates the percentage of HbA1c.

What to Expect

The test is quick and painless. You’ll feel a tiny pinch when blood is drawn, but results are ready in a few days. No special prep is needed unless your doctor instructs otherwise.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HbA1c (Serum)

Frequently asked questions

How often should I get this test?
Typically, people with diabetes check HbA1c every 3–6 months, but your doctor may adjust this based on your treatment plan and blood sugar goals.
What do my results mean?
Results are usually reported as a percentage (e.g., 5.7%–6.4% is prediabetes; 6.5% or higher is diabetes). Your doctor will interpret results in the context of your overall health and symptoms.
Can I eat or drink before the test?
No special diet is required, but avoid sugary drinks or foods for 2 hours before testing if instructed by your doctor to avoid interference.
  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