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Creat24hurmscnc

Published: July 31, 2026Updated: August 16, 2026

This test measures the amount of creatinine in your urine collected over 24 hours to assess how well your kidneys are functioning.

Quick summary

{"Creatinine is a waste product that muscles produce and kidneys filter out","A 24-hour urine collection provides a more accurate picture of kidney function than a single urine sample","Abnormal results may indicate kidney disease, muscle disorders, or other health conditions","You will receive special containers and instructions for collecting all urine over 24 hours","Certain medications and diet can affect test results"}

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

Key facts at a glance

LOINC
35251-8
Short code
UCR24
Synonyms
Creat 24h Ur-msCnc
Category
kidney
Sample
urine
Container
Clean, labeled 24-hour urine collection container, preferably with no preservatives
Units
not specified
Ref low
600
Ref high
2000
Fasting
false
Population
adult
Sex
all
Age range
≥ 0 years
Method
Enzymatic or Jaffe kinetic colorimetric method
CPT
82570
SNOMED
365761006
Specimen volume
Complete 24-hour collection (typical volume 1000-2000 mL depending on patient hydration)
Stability
Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C): 30 days
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What is this test?

The 24-hour urine creatinine test measures how much creatinine is eliminated in your urine over a 24-hour period. Creatinine is a chemical waste product generated from normal muscle metabolism. Healthy kidneys filter creatinine from the blood and excrete it in urine. This test helps doctors evaluate how well your kidneys are working to remove this waste product from your body.

How is the test performed?

You will be given one or more special containers for urine collection. On the morning of the test, you will start by urinating and discarding that first sample, noting the exact time. Then, for the next 24 hours, you will collect all urine in the provided container(s). This includes the first urine of the next morning. Keep the collection in a cool place, such as a refrigerator, during the collection period. Return the complete collection to your healthcare provider's lab as instructed.

Why is this test important?

This test is important because it helps doctors assess kidney function. The amount of creatinine excreted in urine over 24 hours relates to muscle mass and kidney function. By comparing the creatinine level in your urine to levels in your blood, doctors can calculate how efficiently your kidneys are filtering waste. This is more reliable than a single urine sample because it accounts for variations throughout the day.

How to prepare for the test?

Before the test, tell your doctor about all medications you are taking, as some drugs can affect creatinine levels. Avoid strenuous exercise for 24 hours before and during the collection, as intense exercise can increase creatinine. Your doctor may advise you to eat your normal diet. It is important to drink adequate fluids unless otherwise directed. Follow all specific instructions provided by your healthcare team.

Reference range

Males: 1.0-2.0 g/24 h; Females: 0.8-1.8 g/24 hnot specified

Specimen: urine

Complete 24-hour urine collection (discard first void, collect all subsequent urine including final void at 24 h); refrigerate during collection; avoid excessive meat and strenuous exercise; no fasting required

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Does the 24-hour collection have to be exactly 24 hours?
Yes, try to make it exactly 24 hours for accurate results. Start at a convenient time, discard the first morning urine, note the time, then collect all urine including the first morning sample the next day at the same time.
What if I forget to collect a urine sample?
If you miss a sample, note the time and continue collecting. Tell the lab when you return the container so they know the collection may be incomplete. Do not try to make up for missed samples by adding water to the container.
Can I exercise during the collection period?
Avoid strenuous exercise during the 24-hour collection period, as intense exercise can temporarily increase creatinine levels and affect test results. Light activities are generally acceptable.
How will I receive my results?
Your test results will be sent to your healthcare provider, who will discuss them with you at a follow-up appointment. Do not assume normal results if you do not hear from your doctor—always follow up to discuss your test results.
  1. 1
    MedlinePlus - Creatinine Urine TestSource
  2. 2
    Mayo Clinic - Kidney Function TestsSource
  3. 3
    National Kidney Foundation - CreatinineSource

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