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 check via creatinine levels."]
Key facts at a glance
- LOINC
- 7185-2
- Short code
- CATDHIST
- Synonyms
- Cat Dander BasoBnd Ab Qn
- Category
- chemistry
- Sample
- whole-blood
- Container
- Heparinized (sodium or lithium heparin) blood collection tube; EDTA tubes are not preferred as calcium-chelation may interfere with basophil degranulation
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 2 years
- Method
- Allergen-specific basophil histamine release assay (flow cytometry or fluorometric enzyme-linked immunoassay)
- CPT
- 86003
- SNOMED
- 395112001
- Specimen volume
- 5-10 mL whole blood
- Stability
- Process within 2 hours of collection at room temperature (20-25°C); do not refrigerate or freeze as basophil viability is compromised
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 24–72 hours
- Order
- routine
Why This Test Matters
Creatinine is a byproduct of muscle breakdown and is normally filtered out of your blood by your kidneys. High levels can indicate reduced kidney function, while low levels may suggest overhydration or muscle wasting. This test is a key part of evaluating kidney health and overall body fluid balance.
How the Test Works
A small blood sample is taken from your arm. The lab analyzes the sample to measure creatinine concentration using a specialized chemical test. Results are compared to reference ranges to determine if your kidneys are functioning as expected.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to avoid certain medications or supplements that could affect results. Drinking extra water before the test can dilute your blood slightly, but this does not change the test’s purpose.
What the Results Mean
Results are typically reported in milligrams per deciliter (mg/dL) or micromoles per liter (µmol/L). While exact reference ranges vary by lab, higher than normal levels may signal kidney problems, while very low levels could warrant further investigation into hydration status or muscle health.
Reference range
Negative: < reference threshold specific to assay methodology; Positive: ≥ reference threshold indicating detectable cat dander-specific histamine release from basophilsN/A
No fasting required. Patient should inform clinician of all current medications, especially antihistamines, corticosteroids, and leukotriene modifiers, as these may suppress histamine release. Discontinuation of antihistamines for 5-7 days prior to testing may be recommended per clinician discretion.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Creatinine
Frequently asked questions
What does a high creatinine level mean?
Can diet or exercise affect creatinine levels?
Can I take anything before the test?
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