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Creatinine Clearance (from wrist blood sample)

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

This test measures how well your kidneys filter waste products from your blood, using a sample taken from your wrist. It helps assess kidney function and blood flow.

Quick summary

["This test helps doctors check how well your kidneys are working and if your blood pressure or fluid balance needs adjustment."]

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

Key facts at a glance

LOINC
37433-0
Short code
CT Wrist-R
Synonyms
CT Wrist-R
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ct
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 This Test Matters for Kidney Health

Creatinine clearance is a key measure of kidney function because it reflects how efficiently your kidneys remove waste products like creatinine from your blood. Unlike simple blood tests, which only check creatinine levels, clearance accounts for how much blood passes through your kidneys each minute.

How the Test Works

Your doctor will take a blood sample from your wrist (usually an arm vein) and may also ask you to collect a 24-hour urine sample. The test compares the creatinine levels in your blood and urine to estimate how well your kidneys are filtering waste.

When You Might Need This Test

Doctors order creatinine clearance when they suspect kidney problems, monitor chronic kidney disease, evaluate blood pressure medications, or assess fluid balance. It’s also used before surgeries or procedures that may affect kidney function.

What to Expect Before the Test

No special preparation is needed, but you may be asked to avoid certain medications (like NSAIDs) that could affect kidney function. Drink plenty of water the day before if you’re collecting urine, but don’t overdo it—your doctor will guide you.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine Clearance

Frequently asked questions

What does a low creatinine clearance mean?
A lower-than-expected clearance may indicate kidney damage, poor blood flow, or conditions like heart failure or dehydration. It can also signal early kidney disease or blockages in the urinary tract.
What does a high creatinine clearance mean?
Rarely, very high clearance might suggest overhydration or unusual kidney function, but it’s more commonly seen in healthy individuals with normal kidney function. Always discuss results with your doctor.
How often should I get this test?
Your doctor will determine frequency based on your health. People with kidney disease may need it monthly or more often, while others with stable conditions might check it yearly or less.
  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