Creat6hurmrate
This test measures the amount of creatinine excreted in urine over 6 hours to assess kidney function.
{"Creatinine is a waste product from muscle metabolism filtered by kidneys","This test helps evaluate how well your kidneys are working","A 6-hour urine collection is required for accurate measurement","Results help calculate creatinine clearance rate","Abnormal results may indicate kidney disease or dysfunction"}
Key facts at a glance
- LOINC
- 12587-2
- Short code
- U Creat 6h
- Synonyms
- Creat 6h Ur-mRate
- Category
- kidney
- Sample
- urine
- Container
- Clean sterile urine collection container or graduated urine collection container
- Units
- not specified
- Ref low
- 250
- Ref high
- 500
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Enzymatic method or Jaffe colorimetric reaction
- CPT
- 82570
- SNOMED
- 271718004
- Specimen volume
- Complete 6-hour urine collection (volume typically 500-2000 mL depending on urine output)
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 72 hours; Frozen (-20°C): 30 days
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 24–72 hours
- Order
- routine
What is this test?
The 6-hour urine creatinine test measures the amount of creatinine that your kidneys filter and excrete in your urine over a 6-hour period. Creatinine is a waste product produced naturally by your muscles as part of normal metabolism. Healthy kidneys filter creatinine from your blood and eliminate it through urine.
Why is this test performed?
This test is primarily used to evaluate kidney function. By measuring how much creatinine is excreted in urine over a specific time period, healthcare providers can calculate creatinine clearance—a key indicator of how well your kidneys are filtering waste from your blood. It may also be used to monitor kidney disease progression or assess the effectiveness of treatment.
How to prepare for the test?
Before the test, your healthcare provider will give you specific instructions. Generally, you should avoid strenuous exercise for 24 hours before the test, as intense physical activity can increase creatinine levels. Inform your doctor about any medications or supplements you are taking, as some substances may affect test results. You will be provided with a special container to collect all urine during the 6-hour period.
What happens during the test?
You will be asked to collect all urine you produce during a 6-hour period. At the start of the collection time, you will empty your bladder and record the time. For the next 6 hours, every drop of urine must be collected in the provided container. At the end of 6 hours, you will empty your bladder one final time and add this sample to the container. The container should be kept refrigerated or in a cool place until delivered to the laboratory.
Understanding the results
Normal creatinine excretion varies based on factors such as age, gender, muscle mass, and body size. Higher than normal creatinine excretion may indicate kidney problems, while lower than normal levels may suggest decreased kidney function or other conditions. Your healthcare provider will interpret your results in context with other tests and your overall health status.
Reference range
Adult males: 250-500 mg/6h; Adult females: 200-450 mg/6h (approx. from 24h excretion rates)not specified
Complete timed 6-hour urine collection required (discard first void at start, collect all urine including final void at end); refrigerate specimen during collection. No fasting or special diet usually needed.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Is the 6-hour urine collection painful?
What can affect my test results?
How long does it take to get results?
Do I need to fast before this test?
What happens if my results are abnormal?
Sources
- 1
- 2
- 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