Serum or Plasma Creatinine Concentration (Mass)
This test measures the amount of creatinine, a waste product from muscle metabolism, in your blood or plasma. It helps assess how well your kidneys are filtering blood.
["A creatinine test helps check kidney function by measuring waste in your blood."]
Key facts at a glance
- LOINC
- 2039-6
- Short code
- CEA
- Synonyms
- CEA SerPl-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top vacutainer tube; plasma may be collected in heparin or EDTA tubes
- Units
- N/A
- Ref low
- 0
- Ref high
- 3
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Chemiluminescent Immunoassay (CLIA) or Electrochemiluminescent Immunoassay (ECLIA)
- CPT
- 82378
- SNOMED
- 82930-6
- Specimen volume
- 1.0 mL serum or plasma (minimum 0.5 mL)
- Stability
- Room temperature: 8 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 6 months. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 150
- Icterus max
- 50
- TAT
- 4–24 hours
- Order
- routine
Why This Test Matters
Creatinine is a byproduct of muscle breakdown and is normally filtered out by your kidneys. High levels may indicate poor kidney function, while low levels could suggest dehydration or overhydration. This test is often used alongside other kidney function tests to monitor conditions like chronic kidney disease or acute kidney injury.
What to Expect Before the Test
No special preparation is needed for this test. You may have a blood draw (serum/plasma) or a urine sample collected, depending on the specific test ordered. If your doctor asks for a 24-hour urine sample, follow their instructions carefully to collect all urine over that period.
What the Results Mean
Results are typically reported as a concentration (e.g., milligrams per deciliter or micromoles per liter). While reference ranges vary by lab, higher-than-normal levels may signal kidney problems, while very low levels may need further investigation to rule out other causes like muscle disorders or dehydration.
Common Conditions Monitored
This test is commonly used to diagnose and monitor kidney diseases, such as chronic kidney disease, acute kidney injury, and glomerular diseases. It may also be checked in people with diabetes, high blood pressure, or other conditions affecting kidney function.
Reference range
Non-smokers: <3.0 ng/mL (may vary by laboratory and assay manufacturer); Smokers: up to 5.0 ng/mL may be considered within normal limitsN/A
No fasting required. Specimen should be collected prior to initiation of chemotherapy, radiation therapy, or surgical intervention when used for baseline monitoring. Avoid hemolyzed or lipemic specimens when possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Kidney Function and Health
Short name
Creatinine Level
Frequently asked questions
What causes high creatinine levels?
What causes low creatinine levels?
How often should I get this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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 14, 2026. · Read our editorial policy