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Hemoglobin A1c (HbA1c) with mass concentration measurement

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

This test measures the percentage of hemoglobin that is bound to glucose over the past 2–3 months, reflecting your average blood sugar levels during that time.

Quick summary

["HbA1c 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
719-5
Short code
Hgb CSF-mCnc
Synonyms
Hgb CSF-mCnc
Category
hematology
Sample
csf
Container
Sterile tube
Units
N/A
Ref low
12
Ref high
17.5
Critical range
7 N/A – 20 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
85018
SNOMED
900000000000003004
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

What HbA1c Test Measures

HbA1c is a form of hemoglobin (the protein in red blood cells that carries oxygen) that has attached glucose molecules. It reflects your average blood sugar levels over the past 2–3 months, giving doctors a clearer picture of how well your blood sugar has been controlled over time.

Why It’s Used

Doctors use HbA1c to diagnose type 1 and type 2 diabetes, monitor treatment progress, and assess long-term blood sugar control in people with diabetes or prediabetes.

How It’s Performed

A small blood sample is taken from your arm, usually by a healthcare professional. The sample is sent to a lab where it’s analyzed to determine the percentage of HbA1c in your blood.

What the Results Mean

Results are typically reported as a percentage. While exact reference ranges vary by lab, higher levels may indicate poor blood sugar control, while lower levels may suggest better control. Your doctor will interpret results in the context of your overall health and treatment plan.

Reference range

Adult males: 13.5-17.5 g/dL; Females: 12.0-16.0 g/dLN/A

Specimen: csf

No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

HbA1c

Frequently asked questions

How often should I get this test?
Typically, people with diabetes should get an HbA1c test every 3–6 months to monitor their blood sugar control. Your doctor may recommend more frequent testing if your blood sugar levels are unstable or if you’re adjusting your treatment plan.
What do my results mean if they’re outside the normal range?
If your HbA1c is higher than recommended (typically above 7%), it may indicate poor blood sugar management and could increase your risk of diabetes-related complications. If it’s lower than expected, you may be managing your blood sugar well, but your doctor may still check for other factors.
Can lifestyle changes affect HbA1c results?
Yes, diet, exercise, and medication adherence can impact HbA1c levels. Small, consistent lifestyle changes—like eating balanced meals, staying active, and managing stress—can help improve blood sugar control over time.
  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