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Iron and Creatinine, 24-Hour Urine

Published: August 9, 2026Updated: August 17, 2026

A 24-hour urine test measures iron excretion and creatinine. Creatinine may be used to help assess collection adequacy and calculate an iron-to-creatinine ratio.

Quick summary

["This test measures how much iron your body releases in urine over one day and may help evaluate iron overload or depletion."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
53149-1
Short code
Iron/Creat 24h Ur-sRto
Synonyms
Iron/Creat 24h Ur-sRto
Category
kidney
Sample
urine
Container
Sterile urine container
Units
N/A
Ref low
60
Ref high
170
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
83540
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What is this test?

This test measures iron and creatinine in all urine collected over 24 hours. The results may also be expressed as an iron-to-creatinine ratio, which helps account for differences in urine concentration and muscle mass.

Why might I need this test?

A clinician may order this test to evaluate increased iron loss, assess possible iron overload, or investigate an abnormal iron level. Creatinine helps determine whether the urine collection appears adequate.

How is the test performed?

You collect all urine for exactly 24 hours, usually beginning after emptying your bladder. The container and collection instructions should be followed carefully, and the total volume is recorded when the sample is submitted to the laboratory.

How do I prepare for the test?

Follow the laboratory's instructions, including how long and when to collect urine. If you have recently taken iron supplements or iron-containing medicines, tell the clinician because they may affect the results.

Reference range

NCBI: Serum Iron Male 65-180; Female 50-170 µg/dLN/A

Specimen: urine

Fasting for 12 hours preferred. Iron supplements should be stopped 24 hours before if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

24-Hour Urine Iron and Creatinine

Frequently asked questions

Do I need to fast for this test?
Fasting is generally not required, but follow any specific instructions from the laboratory or clinician. Mention recent iron supplements or iron-containing medicines.
What happens if part of the urine collection is missed?
The result may not accurately represent your total iron excretion. Contact the laboratory for instructions about restarting the collection.
Why is creatinine included?
Creatinine helps show whether a full-day collection was obtained and may be used with urine iron to calculate a ratio. This provides context for interpreting the iron result.
  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 17, 2026. · Read our editorial policy