Serum Creatinine (Creatinine Level)
This test measures the amount of creatinine, a waste product from muscle metabolism, in your blood. Creatinine levels help assess how well your kidneys are filtering blood.
["Your kidneys filter waste from blood; this test checks kidney function."]
Key facts at a glance
- LOINC
- 41844-2
- Short code
- N men sg A+B+C+W135+Y+EcK1 Ag Ser Ql Agg
- Synonyms
- N men sg A+B+C+W135+Y+EcK1 Ag Ser Ql Agg
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 22
- Ref high
- 198
- Critical range
- — – 10000 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- aggl
- CPT
- 82553
- 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 normally filtered out by your kidneys. High levels may indicate kidney problems, while low levels could suggest muscle disorders or dehydration. Your doctor may order this test to monitor kidney health, especially if you have conditions like diabetes, high blood pressure, or a history of kidney disease.
What to Expect Before the Test
No special preparation is needed for this test. You may have a small needle inserted into your arm to draw blood. If you’re on a low-protein diet or have recently exercised, let your doctor know—these can affect results.
Possible Results & What They Mean
Results are typically reported in milligrams per deciliter (mg/dL). Very high levels may signal kidney issues, while very low levels could raise concerns about muscle metabolism or hydration status. Your doctor will interpret results in the context of your overall health.
Common Causes of Abnormal Results
Kidney disease (e.g., chronic kidney disease), dehydration, muscle disorders, or certain medications (like NSAIDs) can alter creatinine levels. High levels may also occur with severe illness or blockages in the urinary tract.
Reference range
Adult males: 22-198 U/L; Females: 22-198 U/LN/A
No special preparation required. Inform provider of any chest pain or symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
None
Frequently asked questions
How often do I need this test?
Can diet affect this test?
What if my results are out of range?
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 17, 2026. · Read our editorial policy