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Estimated glomerular filtration rate (eGFR) using serum creatinine

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

This test estimates how well your kidneys are filtering waste products from your blood using a simple blood sample. It helps assess kidney function over time.

Quick summary

["Your eGFR helps doctors track kidney health and guide treatment decisions."]

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

Key facts at a glance

LOINC
104253-0
Short code
LV EF US.2D.A4C+Estimated
Synonyms
LV EF US.2D.A4C+Estimated
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
us-d-a-c-estimated
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

Kidneys play a vital role in removing waste and balancing fluids in your body. When they don’t work as well, harmful substances can build up, leading to serious health risks. This test provides a snapshot of kidney function by measuring how efficiently your kidneys filter blood.

How the Test Works

Your blood is drawn and sent to a lab. The lab uses a formula that includes your serum creatinine levels (a waste product from muscle metabolism) and other factors like age, sex, and body size to estimate how well your kidneys are filtering blood.

What to Expect Before the Test

No special preparation is needed for this blood test. You may have a slight bruise or soreness at the needle site, but this usually goes away quickly. If you’re on certain medications that affect kidney function, let your doctor know before the test.

Possible Results and Next Steps

Results are typically reported as a number (e.g., 60 mL/min/1.73 m²). Lower numbers may indicate reduced kidney function, while higher numbers suggest normal or better-than-average kidney function. Your doctor will discuss your results in detail and may recommend follow-up tests or adjustments to your care plan.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

eGFR (Serum Cr)

Frequently asked questions

What does an abnormal eGFR mean?
An eGFR below the normal range may signal early kidney problems, even if you don’t have symptoms. It can help detect kidney disease before it worsens, allowing for early treatment. Repeated tests over time can track changes in kidney function.
Can diet or medications affect my eGFR?
Yes, certain foods, supplements, and medications can influence kidney function. For example, excessive salt, potassium-rich foods, or medications like NSAIDs (e.g., ibuprofen) may affect kidney health. Always discuss your diet and medications with your doctor to ensure they’re safe for your kidneys.
How often should I get this test?
Your doctor will determine how often you need this test based on your health status. People with known kidney issues may need tests more frequently, while others with no history of kidney problems may only need it periodically, such as during routine check-ups or if you have risk factors (e.g., diabetes, high blood pressure).
  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