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Creatinine Clearance (Serum-Based, 24-Hour Urine Collection)

Published: August 9, 2026Updated: August 16, 2026

This test measures how well your kidneys filter waste products from your blood, using a 24-hour urine sample and your serum creatinine level.

Quick summary

["Assesses kidney function by estimating how efficiently your kidneys remove waste from blood over 24 hours."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
14203-4
Short code
C trach C IgG Titr Ser IF
Synonyms
C trach C IgG Titr Ser IF
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
8
Ref high
61
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
if
CPT
82977
SNOMED
3110003
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 It’s Done

Your doctor may order this test if you have symptoms like fatigue, swelling, or frequent urination, or if you have conditions like high blood pressure, diabetes, or chronic kidney disease. It helps determine how well your kidneys are working to clear waste products from your blood.

How It Works

You’ll collect all urine for a full 24-hour period, then provide a blood sample. The test calculates creatinine clearance by comparing your urine output and creatinine levels to your serum creatinine level.

What to Expect

You’ll need to start urine collection at the same time each morning, discard the first void, and collect every urine sample for 24 hours. Bring all urine samples to the lab in a sealed container. Your blood will be drawn in a standard vein access procedure.

Possible Results

Results are expressed in milliliters per minute (mL/min) or liters per minute (L/min). Lower than expected results may indicate kidney problems, while higher results could suggest overhydration or other conditions.

Reference range

Adult males: 8-61 U/L; Adult females: 5-36 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Creatinine Clearance

Frequently asked questions

What does a low creatinine clearance mean?
A low creatinine clearance suggests your kidneys may not be filtering waste products efficiently, which could indicate chronic kidney disease, reduced kidney mass, or other kidney-related issues. Early detection helps manage conditions like diabetes or hypertension.
How often should I get this test?
Your doctor will determine how often you need this test based on your health condition, symptoms, and kidney function. Regular monitoring may be needed if you have chronic kidney disease, diabetes, or other risk factors.
Can I eat or drink normally before this test?
Yes, you can eat and drink normally before the test, except for collecting urine. Follow your doctor’s specific instructions regarding fluid intake during the 24-hour urine collection period.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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