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Serum Creatinine with Glomerular Filtration Rate (GFR) Estimation (using a modified equation)

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

This test measures your kidney function by estimating how well your kidneys filter waste products from your blood.

Quick summary

["Kidney function assessment using creatinine levels and a mathematical formula."]

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

Key facts at a glance

LOINC
107913-6
Short code
HLA I & II IgG SerPl Ql
Synonyms
HLA I & II IgG SerPl Ql
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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

What Does This Test Measure?

Creatinine is a waste product your kidneys normally filter from your blood. The test measures your serum creatinine level and uses it, along with other factors, to estimate how well your kidneys are working. This helps determine your Glomerular Filtration Rate (GFR), a measure of kidney function.

Why Is This Test Important?

A GFR estimate helps doctors monitor kidney health, especially in people with diabetes, high blood pressure, or other conditions that can affect kidneys. It can also guide decisions about medications that may be harmful to kidneys.

How Is This Test Performed?

A small blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where creatinine levels are measured using a specialized method to calculate GFR.

What Are Common Causes of Abnormal Results?

Low GFR may indicate kidney disease or damage, while very high levels could suggest dehydration or muscle breakdown. Other conditions, such as heart or liver disease, can also influence creatinine levels.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine GFR

Frequently asked questions

What does a ‘normal’ result mean for my kidney function?
A ‘normal’ result doesn’t mean your kidneys are perfectly healthy, but it suggests your kidneys are filtering waste products effectively. Your doctor will interpret the result in the context of your overall health and other test results.
How often should I get this test if I have kidney-related conditions?
Your doctor will determine the frequency based on your specific health needs. Regular monitoring is often recommended for people with diabetes, high blood pressure, or a history of kidney issues to track changes over time.
Can diet or exercise affect my creatinine levels?
Dietary changes, such as reducing protein intake, can sometimes impact creatinine levels, but results depend on overall kidney function. Exercise generally supports kidney health, but it’s best discussed with your healthcare provider before making significant changes.
  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