Lab test glossary · Kidney
eGFR: what it means
Also known as: estimated glomerular filtration rate, GFR
eGFR estimates how well your kidneys filter waste, calculated from creatinine; lower values indicate reduced kidney function.
What it measures
eGFR (estimated glomerular filtration rate) is a calculation — based on your creatinine plus age and sex — that estimates how many milliliters of blood your kidneys filter per minute. It's the standard way kidney function is staged.
Typical range
An eGFR of 90+ is generally considered normal, and values are staged downward from there; a result under 60 that persists for three months defines chronic kidney disease. Your clinician interprets it in context.
Reference ranges differ between labs and are printed on your own report — always read your result against that range, not a general one.
What a high result can mean
- Higher values are generally reassuring
A high value is a starting point for a conversation, not a diagnosis — many causes are benign or temporary.
What a low result can mean
- Reduced kidney function from diabetes, high blood pressure, or other kidney disease
- Dehydration (can transiently lower it)
- Naturally declines somewhat with age
Why the trend matters
Kidney function changes slowly, so eGFR is one of the clearest examples of a test where the multi-year trend is far more meaningful than any single number.
When to talk to your doctor
An eGFR under 60, or one that's declining over time, should be discussed with your doctor.
Frequently asked questions
What is a normal eGFR?
An eGFR of 90 or above is generally considered normal; a value under 60 that persists for three months defines chronic kidney disease, which your clinician stages and interprets in context.
Does a low eGFR mean I have kidney disease?
Not always — eGFR can dip transiently with dehydration and declines somewhat with age, so a low value is read alongside the trend and other kidney tests before any conclusion.
This page is general education about a common lab test — it isn’t medical advice and can’t interpret your specific result. What a value means depends on your history, symptoms, and the rest of your labs, which is a conversation for you and your clinician.