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Glomerular Filtration Rate (GFR) calculated from serum creatinine and estimated creatinine clearance

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

This test measures how well your kidneys are filtering waste from your blood, using a formula that combines your serum creatinine level with other factors.

Quick summary

["GFR helps assess kidney function and identify early kidney damage or disease."]

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

Key facts at a glance

LOINC
81604-1
Short code
NM Kidney Views for GFR W RNC IV
Synonyms
NM Kidney Views for GFR W RNC IV
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
nm
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 is GFR important?

GFR is a key indicator of kidney health because it reflects how effectively your kidneys remove waste products like creatinine from your blood. It’s often used alongside other tests to monitor chronic kidney disease or evaluate kidney function before certain treatments.

How is GFR calculated?

GFR is estimated using a formula (like the CKD-EPI equation) that takes into account your serum creatinine level, age, sex, and sometimes race. Your healthcare provider may also consider your urine creatinine clearance if available.

What does a low GFR mean?

A lower GFR suggests impaired kidney function, which may indicate early kidney disease. Very low levels can mean advanced kidney damage or failure, requiring medical attention.

What causes changes in GFR?

Kidney disease, dehydration, high blood pressure, diabetes, or certain medications can affect GFR. Other factors like age, obesity, or genetic conditions may also play a role.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

GFR (estimated)

Frequently asked questions

What does a normal GFR value mean?
A normal GFR typically falls within a range that indicates healthy kidney function, but exact values depend on your age, sex, and other health factors. Your doctor will interpret results in the context of your overall health.
Can diet or lifestyle changes affect GFR?
Yes, diet (e.g., high protein intake), hydration levels, and lifestyle habits (e.g., smoking, alcohol use) can influence kidney function. Managing blood pressure, controlling diabetes, and staying hydrated may help support kidney health.
How often should GFR be checked?
Your doctor may recommend GFR testing periodically if you have risk factors for kidney disease, such as diabetes, high blood pressure, a family history of kidney problems, or other health conditions affecting the kidneys.
  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