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24-Hour Urinary Mass Concentration of Creatinine (or Protein, depending on context; often measured as a marker of renal function or filtration)

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

This test measures the amount of creatinine (or sometimes protein) in your urine over a 24-hour period. It helps doctors assess how well your kidneys are filtering waste from your blood.

Quick summary

["Helps check kidney function and detect potential issues early."]

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

Key facts at a glance

LOINC
3795-2
Short code
MTX 24h p SerPl-mCnc
Synonyms
MTX 24h p SerPl-mCnc
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 Kidney Health

Kidneys normally filter waste products like creatinine from your blood. If they’re not working well, waste can build up, causing problems. This test helps track how efficiently your kidneys remove these substances over time.

What to Expect Before the Test

You’ll collect all your urine for a full 24 hours, typically starting after midnight the night before the test and ending the same time the next day. A healthcare provider will give you a clean container to store the sample. Drink plenty of fluids but avoid foods that might affect urine color (like beets or berries) unless instructed otherwise.

How the Test Works

The collected urine is tested in a lab to measure the total amount of creatinine (or protein) excreted. The results are compared to a baseline to see if your kidneys are working as expected.

Common Reasons for This Test

Doctors may order this test if you have symptoms like swelling, frequent urination, fatigue, or if they suspect kidney disease, diabetes, or other conditions affecting fluid balance.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Abnormal results may indicate kidney dysfunction, fluid retention, or other metabolic issues. High levels could signal poor kidney function, while low levels might suggest dehydration or other problems. Regular monitoring helps manage chronic conditions like diabetes or hypertension.

Short name

24h Urine Creatinine/Protein Test

Frequently asked questions

Will I need to change my diet before the test?
No special diet is required, but avoid excessive salt or certain medications that might affect urine output unless advised by your doctor.
Can I take my usual medications on test day?
Yes, but always check with your doctor first. Some medications (like certain diuretics) may affect urine volume or composition.
How long will I wait for results?
Results typically arrive within 1–3 business days, depending on lab processing times. Your doctor will discuss them with you during your follow-up visit.
  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