Serum or Plasma Creatinine Concentration (Substance Concentration)
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 and detect early kidney problems."]
Key facts at a glance
- LOINC
- 42687-4
- Short code
- XR Ribs-Bl 2V
- Synonyms
- XR Ribs-Bl 2V
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- xr
- 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 levels can rise if your kidneys aren’t working as well as they should, which may indicate kidney disease or damage. It’s often used alongside other tests to monitor kidney health, especially in people with diabetes, high blood pressure, or a family history of kidney issues.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to avoid certain medications (like pain relievers) that can affect results. If you’re on dialysis, your doctor may adjust timing. Drink plenty of water the day before to help your kidneys process waste normally.
What the Results Mean
Results are compared to a general reference range, but your actual values may differ based on age, sex, muscle mass, and health. High levels may signal kidney problems, while very low levels could suggest muscle loss or other conditions. Your doctor will interpret results in the context of your overall health.
Common Causes of Abnormal Results
High creatinine levels can be caused by kidney disease, dehydration, severe illness, or conditions that reduce blood flow to the kidneys. Low levels may occur with muscle disorders, liver disease, or overhydration. Other factors, like certain medications or lab errors, can also influence results.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated creatinine is a key marker for kidney function and is often used to diagnose or monitor chronic kidney disease (CKD). It helps guide treatment decisions, such as managing blood pressure, diabetes, or adjusting medications that may strain the kidneys. Repeated tests can track kidney health over time, especially in people at higher risk.
Short name
Creatinine
Frequently asked questions
How often should I get this test?
Does diet affect creatinine levels?
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