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Hemoglobin A1c (HbA1c) with 24-hour urine collection for measurement of free hemoglobin

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

This test measures hemoglobin that remains attached to red blood cells over the past 2–3 months, along with a specialized urine sample to assess free hemoglobin levels.

Quick summary

["Helps track long-term blood sugar control and identifies potential hemoglobin-related conditions."]

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

Key facts at a glance

LOINC
7394-0
Short code
H maydis IgE Qn
Synonyms
H maydis IgE Qn
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

Why This Test Matters for Blood Sugar Management

HbA1c is a key measure of average blood sugar levels over time, reflecting how well diabetes or prediabetes is managed. This test may also include a urine sample to check for free hemoglobin, which can indicate conditions like hemolysis (red blood cell breakdown).

How the Test Works

The blood test measures HbA1c via immunoassay, while the urine sample assesses free hemoglobin concentration. Results help doctors assess both long-term glucose control and red blood cell health.

What to Expect Before the Test

No special preparation is needed for the blood draw, but a 24-hour urine collection may require collecting all urine in a container. Follow your provider’s instructions carefully to ensure accurate results.

Common Causes of Abnormal Results

High HbA1c levels often signal poor blood sugar control, while elevated free hemoglobin in urine may indicate hemolysis or other blood disorders. Low levels could reflect well-controlled diabetes or rare conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HbA1c (Urine Free)

Frequently asked questions

How often should I get this test?
Typically recommended annually for people with diabetes or prediabetes, but your doctor may adjust frequency based on your health status and treatment plan.
What do my results mean if they’re outside the normal range?
Results outside reference ranges may prompt further testing or adjustments to your diabetes management plan, including diet, medication, or lifestyle changes.
Can diet or exercise affect this test?
Yes—diet, exercise, and blood sugar levels can influence HbA1c. For the urine sample, hydration and avoiding certain medications (like NSAIDs) may impact free hemoglobin detection.
  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