Plasma Creatinine Concentration
This test measures the amount of creatinine, a waste product from muscle metabolism, in your blood plasma. It helps assess kidney function by reflecting how well your kidneys filter blood.
["A creatinine test helps check kidney health and diagnose kidney disease early."]
Key facts at a glance
- LOINC
- 33356-7
- Short code
- PT 1h NP Cont PPP
- Synonyms
- PT 1h NP Cont PPP
- Category
- chemistry
- Sample
- plasma
- Container
- Lavender-top (EDTA) or Green-top (Heparin)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- coag-tissue-factor-induced-factor-substitution-h-post-incubation-after-addition-of-normal-plasma
- CPT
- 85610
- SNOMED
- 396252006
- 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 Is This Test Done?
Your healthcare provider may order this test to monitor kidney function, especially if you have symptoms like swelling, fatigue, or changes in urine output. It’s also used before certain procedures, to check for kidney problems in people with diabetes, high blood pressure, or other health conditions that can affect kidneys.
What to Expect Before the Test
No special preparation is needed unless instructed by your doctor. You may be asked to fast for 8–12 hours before the test if it’s part of a larger panel, but a simple creatinine test can be done anytime. Drink plenty of water the day before if you’re dehydrated.
What Happens During the Test?
A small blood sample is drawn from a vein, usually in your arm. The process takes a few minutes, and you may feel slight discomfort, but it’s quick and not painful. The blood is sent to a lab for analysis.
What the Results Mean
Higher than expected levels may suggest kidney problems, while lower levels could indicate dehydration or muscle breakdown. Your results will be compared to a reference range specific to your age, sex, and health status.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Creatinine levels are a key marker for kidney function because they reflect how well your kidneys filter waste products from blood. Elevated levels often signal impaired kidney function, which can lead to kidney disease, fluid buildup, or other complications. Regular monitoring helps manage conditions like diabetes or hypertension that increase kidney risk.
Short name
Creatinine (Plasma)
Frequently asked questions
What causes creatinine levels to change?
How often should I get this test?
Can diet affect creatinine levels?
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