Serum or Plasma Creatinine Concentration (Mass Concentration)
This test measures the level 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
- 105762-9
- Short code
- Mtb oxyR-ahpC INH hl res mut Islt/Spm
- Synonyms
- Mtb oxyR-ahpC INH hl res mut Islt/Spm
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- molgen
- 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
Your kidneys normally filter waste products, including creatinine, from your blood. High levels may indicate kidney problems, while low levels could suggest dehydration or muscle breakdown. This test is often used alongside other measures to monitor kidney health, especially in people with risk factors like diabetes or high blood pressure.
What to Expect Before the Test
No special preparation is needed for this test. You may have a blood draw (serum/plasma) or, less commonly, a urine sample (though the slug indicates serum/plasma). Avoid strenuous activity or heavy meals 12 hours before if blood is drawn. If you’re on a low-protein diet, discuss it with your doctor, as it may affect results.
What the Results Mean
Results are compared to a reference range based on age, sex, and muscle mass. Elevated levels may signal kidney disease, while persistently low levels might warrant further investigation for conditions like muscle disorders or dehydration.
Common Causes of Abnormal Results
High creatinine levels can result from kidney disease, dehydration, or conditions that increase muscle breakdown (e.g., severe illness). Low levels may occur with dehydration, malnutrition, or certain medications. Always discuss results with your healthcare provider.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Creatinine is a critical marker for kidney function. It reflects how well your kidneys remove waste from blood. Chronic kidney disease (CKD) often shows early signs with elevated creatinine, so regular monitoring is essential for people at risk. This test is also used to guide dialysis timing or adjust medications like lithium or contrast dyes that affect kidney function.
Short name
Creatinine
Frequently asked questions
Will I need to prepare for this test?
Can diet affect my creatinine test results?
What if my results are outside the normal 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 16, 2026. · Read our editorial policy