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Creatinine, Urine

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

Measures creatinine in urine to help assess kidney function and determine how much creatinine is being excreted or concentrated in a urine sample.

Quick summary

["Urine creatinine helps clinicians evaluate kidney function and interpret related urine measurements."]

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

Key facts at a glance

LOINC
28598-1
Short code
AAA/Creat Ur-Rto
Synonyms
AAA/Creat Ur-Rto
Category
liver
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?

This test measures the amount of creatinine in urine. Creatinine is a waste product made by the muscles and filtered by the kidneys. The result may be reported as a concentration or as the total amount collected, depending on the type of urine sample requested.

Why might I need this test?

Urine creatinine may be used to check kidney function, assess how the kidneys are handling fluid, or provide a reference value when measuring another substance in urine. It is also commonly included in a 24-hour urine collection.

How is the test performed?

A urine sample is tested in a laboratory to measure its creatinine content. If a 24-hour collection is requested, all urine collected during the specified period must be saved in the provided container and returned according to the collection instructions.

How do I prepare for the test?

Follow the instructions provided with the urine container. For a timed collection, record the start and finish times and collect every urine sample during that period. Your clinician or laboratory will tell you if any dietary or medication changes are needed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine creatinine

Frequently asked questions

Is urine creatinine the same as blood creatinine?
No. Blood creatinine measures creatinine circulating in the blood, while urine creatinine measures the amount present in urine. Both can help clinicians assess kidney function.
Why is urine creatinine sometimes measured over 24 hours?
A 24-hour collection measures the total amount of creatinine excreted rather than only its concentration at one time. This can help evaluate kidney function and quantify substances excreted in urine.
Does drinking a large amount of water affect the result?
It can dilute urine and lower the creatinine concentration without changing the total amount produced. Your clinician will interpret the result based on the type and completeness of the collection.
  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