What is eGFR?
eGFR estimates how many millilitres of blood the kidneys filter per minute. It is calculated from serum creatinine, age, sex, and sometimes race, providing a standardised measure of kidney function.
Kidney function naturally declines slightly with age. A single low eGFR reading is less informative than a trend over time. Chronic kidney disease (CKD) is defined by persistently reduced eGFR and/or markers of kidney damage.
Why might eGFR be low?
A lower eGFR means the kidneys are filtering less blood per minute than expected. Values between 60–89 may warrant monitoring; values below 60 on repeated testing indicate reduced kidney function and are usually investigated further.
This information is educational. A single out-of-range result is rarely the whole picture — a healthcare professional can interpret your numbers alongside your overall health and history.
Context questions that matter
- →Was this result slightly or clearly outside the reference range?
- →Were related markers also high or low?
- →Is this new compared with previous tests?
- →Could recent illness, exercise, fasting, alcohol, supplements, or medication affect it?
- →Do you have symptoms that should be discussed with a clinician?
Markers often reviewed together with eGFR
Clinicians rarely look at one number in isolation. These markers usually accompany eGFR on a kidney function panel and help put the result in context.
Lifestyle considerations
- •Blood pressure control, avoiding NSAIDs long-term, and staying hydrated are key for kidney health
Questions to ask your doctor
- →Should we compare this with creatinine, eGFR, urea and electrolytes?
- →Could hydration, age, muscle mass, or medication affect this low eGFR result?
- →Is this result new, or part of a trend across my previous tests?
Don't guess from one flagged result.
Start with the most relevant panel and see how your markers fit together in plain English.
Frequently asked questions
What does low eGFR mean?
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A lower eGFR means the kidneys are filtering less blood per minute than expected. Values between 60–89 may warrant monitoring; values below 60 on repeated testing indicate reduced kidney function and are usually investigated further.
What is eGFR?
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eGFR estimates how many millilitres of blood the kidneys filter per minute. It is calculated from serum creatinine, age, sex, and sometimes race, providing a standardised measure of kidney function.
Should eGFR be read with eGFR or creatinine?
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Kidney markers are usually interpreted together. Creatinine, eGFR (creatinine-based or cystatin-C-based), urea (BUN), electrolytes and urine markers such as the albumin/creatinine ratio give a fuller picture than any single value.
Can hydration affect kidney-related results?
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Hydration, recent illness, muscle mass, age and some medicines can affect kidney-related markers. A single value is interpreted with these factors and with the trend across previous tests — your doctor can put the number in context using your full report.
What supports healthy eGFR levels?
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Blood pressure control, avoiding NSAIDs long-term, and staying hydrated are key for kidney health