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Plasma Creatinine (with optional 24-hour urine collection for creatinine clearance calculation)

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

This test measures the amount of creatinine, a waste product from muscle metabolism, in your blood or urine. It helps assess kidney function and filter efficiency.

Quick summary

["Kidney function and filtering ability depend on this test."]

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

Key facts at a glance

LOINC
39745-5
Short code
NM Kidney Views W Tc99mDTPA IV
Synonyms
NM Kidney Views W Tc99mDTPA IV
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
nm
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

Creatinine is a byproduct of muscle breakdown and is filtered out by your kidneys. High levels may indicate kidney damage or disease, while low levels could suggest dehydration or other conditions affecting muscle metabolism.

What to Expect Before the Test

No special preparation is needed for a blood test. For a 24-hour urine test, collect all urine over 24 hours in a container provided by your lab. Drink fluids as usual unless instructed otherwise.

What the Results Mean

Blood creatinine levels help doctors evaluate kidney function by measuring how well your kidneys remove waste. Urine creatinine clearance helps determine how efficiently your kidneys filter waste from your blood.

Common Reasons for Testing

Doctors may order this test if you have symptoms like fatigue, swelling, or frequent urination, or if you have a history of kidney disease, high blood pressure, or diabetes.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Creatinine Level

Frequently asked questions

How often should I get this test?
Your doctor will determine the frequency based on your health status, symptoms, and risk factors. Regular monitoring may be needed if you have chronic conditions like kidney disease or diabetes.
What if my results are abnormal?
Abnormal results may prompt further testing or adjustments to your treatment plan, such as medications or lifestyle changes. Follow-up with your healthcare provider to discuss next steps.
Can diet or exercise affect creatinine levels?
Yes, diet (especially protein intake) and muscle activity can influence creatinine levels. Avoid extreme dietary changes or heavy exercise before testing unless advised by your doctor.
  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