Creatinine Clearance (Serum-Based, 24-Hour Urine Collection)
This test measures how well your kidneys filter waste products from your blood, using a 24-hour urine sample and a blood draw. It helps assess kidney function and overall kidney health.
["A creatinine clearance test helps doctors check how well your kidneys are working by measuring how quickly waste products leave your blood."]
Key facts at a glance
- LOINC
- 105026-9
- Short code
- OXA162
- Synonyms
- blaOXA-162 Islt/Spm Ql
- Category
- chemistry
- Sample
- serum
- Container
- Sterile, leak-proof container; transport swab in Amies or Stuart's transport medium; or appropriate bacterial isolate on agar slant/plate. For serum/plasma molecular testing, use EDTA tube or sterile cryovial.
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- molgen
- CPT
- 87153
- SNOMED
- 1007335009
- Specimen volume
- 0.5-1 mL of specimen fluid or sufficient bacterial growth from culture; minimum 100 µL for direct specimen testing
- Stability
- Refrigerated (2-8°C): up to 7 days; Frozen (-20°C or below): up to 30 days for nucleic acid extracts; Room temperature: process within 2 hours. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–48 hours
- Order
- routine
Why This Test Is Done
Your doctor may order this test if they suspect kidney disease, monitor kidney function over time, or evaluate kidney function before certain procedures. It’s also used to check for conditions like chronic kidney disease or to assess kidney function in people with diabetes or high blood pressure.
How the Test Works
To calculate creatinine clearance, your doctor will collect a 24-hour urine sample (usually over 24 hours) and draw a blood sample. The urine sample measures creatinine levels, while the blood sample measures creatinine and other blood components. The test compares these values to estimate how well your kidneys filter waste.
What to Expect Before the Test
You’ll need to collect all urine for a full 24-hour period, starting after your first urine of the day. Drink plenty of fluids to help with urine collection, but avoid excessive caffeine or alcohol, as they may affect results. Your doctor will provide clear instructions on how to properly collect the urine sample.
What to Expect During the Test
The blood draw is quick and usually done in a doctor’s office or lab. The urine collection requires careful timing and may involve multiple visits to the lab or a home collection kit. If you’re unsure about the process, ask your doctor or lab technician for guidance.
Reference range
Negative for blaOXA-162 gene (Not Detected). A positive result indicates the presence of the blaOXA-162 carbapenemase gene, which confers resistance to carbapenem antibiotics.N/A
No special patient preparation required. Specimen should be collected prior to initiation of antimicrobial therapy when possible. Inform the laboratory if the patient has recently received antibiotics, as this may affect organism recovery. Standard infection control precautions should be observed during specimen collection.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Creatinine clearance is a key measure of kidney function. Low levels may indicate kidney damage or disease, while high levels could suggest dehydration or other health issues. It’s often used alongside other tests to diagnose and monitor kidney problems, especially in people with symptoms like fatigue, swelling, or changes in urine output.
Short name
Creatinine Clearance
Frequently asked questions
How long does it take to get the results?
Can I eat or drink normally before the test?
What if I miss my urine collection time?
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