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24-Hour Urine Creatinine, Total Amount

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

Measures the total creatinine excreted in urine over 24 hours. It can help assess kidney function and whether a urine collection was complete.

Quick summary

["This test measures how much creatinine your body removes through the urine over one day."]

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

Key facts at a glance

LOINC
47981-6
Short code
Phe/Creat 24h Ur-Rto
Synonyms
Phe/Creat 24h Ur-Rto
Category
kidney
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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?

Creatinine is a waste product made by the muscles and filtered by the kidneys. This test measures the total amount of creatinine in all urine collected over 24 hours, rather than the concentration in a single urine sample.

Why might I need this test?

A 24-hour urine creatinine measurement can help clinicians assess kidney filtration and calculate other measures, such as creatinine clearance or the amount of a substance excreted each day. It may also be used with another urine test to check whether the collection was complete.

How is the test performed?

You collect all urine for exactly 24 hours, including urine produced during the night. The laboratory then measures the creatinine in the combined collection and may report the total amount excreted during that period.

How do I prepare for the test?

Follow the collection instructions provided by your healthcare professional or laboratory. Urine is often collected in a special container and may need refrigeration; record any urine samples that were missed because an incomplete collection can affect the result.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

A lower-than-expected amount may occur with reduced kidney function, while a higher amount may reflect high muscle mass, intense physical activity, or increased muscle breakdown. Results are also affected by incomplete or unusually long urine collections and should be interpreted alongside other kidney function tests.

Short name

24-Hour Urine Creatinine

Frequently asked questions

Is this the same as a serum creatinine test?
No. Serum creatinine measures creatinine in the blood, while this test measures the total amount excreted in urine over 24 hours.
Do I need to fast for a 24-hour urine creatinine test?
Fasting is generally not required, but you should follow the specific instructions given by your clinician or laboratory.
What happens if I miss part of the collection?
A missed sample can make the total amount appear falsely low. Tell the laboratory about any missed urine so the result can be interpreted appropriately.
  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