Serum Creatinine (Creatinine Level)
This test measures the amount of creatinine, a waste product from muscle metabolism, in your blood. It helps assess how well your kidneys are filtering blood.
["Kidney function depends on this test to detect early kidney problems."]
Key facts at a glance
- LOINC
- 10471-1
- Short code
- CgA IHC
- Synonyms
- CgA Ag Tiss Ql ImStn
- Category
- chemistry
- Sample
- serum
- Container
- Formalin-fixed, paraffin-embedded (FFPE) tissue block or unstained tissue slides
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- immune-stain
- CPT
- 88342
- SNOMED
- 385467004
- Specimen volume
- Tissue block or 4-5 micron thick tissue sections on positively charged slides (minimum 1 slide)
- Stability
- FFPE blocks: Indefinite at room temperature; Unstained slides: Stable for 1 year at room temperature; Fresh tissue: Should be fixed within 1-2 hours of collection
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–72 hours
- Order
- routine
Why Is This Test Done?
Doctors may order this test to check for kidney disease, monitor kidney function in chronic conditions (like diabetes or high blood pressure), or evaluate symptoms such as swelling, fatigue, or changes in urine output. It’s also used before certain surgeries or treatments to ensure kidney health.
What Does a High or Low Result Mean?
High creatinine levels may indicate reduced kidney function or damage, while very low levels could suggest muscle disorders or severe dehydration. However, results alone aren’t diagnostic—they’re part of a bigger picture.
How Is This Test Performed?
A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where creatinine levels are measured using an automated method that detects waste products in your blood.
What Should I Do Before the Test?
No special preparation is needed unless instructed by your doctor. Avoid overhydrating or restricting fluids unless advised, as it may affect results. If you’re on certain medications (like contrast dye for imaging), let your provider know.
Reference range
Positive or Negative (Presence/Absence); Reported as staining intensity and percentage of positive cellsN/A
No special patient preparation required for tissue specimen. Surgical or biopsy tissue should be placed in 10% neutral buffered formalin for proper fixation.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Creatinine levels are a key marker for kidney function. Elevated levels often signal impaired filtration, which can lead to long-term kidney damage if untreated. Regular monitoring helps manage conditions like diabetes or hypertension and prevents complications like fluid buildup or electrolyte imbalances.
Short name
Creatinine
Frequently asked questions
What causes creatinine levels to change?
How often should I get this test?
Does 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