eGFR
Estimated Glomerular Filtration Rate
eGFR estimates how well your kidneys filter waste from your blood. It is usually calculated from creatinine, age and sex. It is not a percentage of kidney function.
Try your eGFR result.
A quick one-marker check. Vita can score it better once it sees the full lab report around it.
What does a low eGFR mean?
A lower result can indicate reduced kidney filtering. A single reading cannot show whether a change is temporary or long-standing. Your previous results and a urine albumin test help explain the picture.
Lower eGFR means less kidney filtering
- Severely reduced
- Below 15 — specialist assessment needed
- Reduced filtering
- 15–59 — review with your clinician
- Mildly reduced
- 60–89 — consider age, trends and urine albumin
- Normal or high filtering category
- 90 or higher — kidney damage can still be present
These categories describe estimated filtering, not a percentage. An eGFR below 60 for at least three months can indicate chronic kidney disease. Values of 60 or higher do not exclude kidney damage: urine albumin and trends still matter. A new drop should be reviewed promptly.
Sources: National Kidney Foundation
What can change this result?
Why it may fall
- Dehydration or a recent illness affecting kidney function.
- Kidney damage, including from diabetes or high blood pressure.
- Higher creatinine after intense exercise or with greater muscle mass can affect the estimate.
What helps put it in context
- Compare with earlier results; a sudden drop and a long-term pattern need different follow-up.
- Review medicines, including frequent use of anti-inflammatory painkillers, with your clinician.
- Managing blood pressure and diabetes helps protect kidney function.
A higher estimate is not proof of better kidneys: low muscle mass can make creatinine-based eGFR look higher. Ask whether a cystatin C or urine albumin test would help.
What should I do next?
- Compare with earlier results and ask whether urine albumin has been checked.
- Discuss a new drop promptly; do not wait three months to seek advice about an unexpected result.
- Ask when to repeat the test and whether a cystatin C estimate would be useful.
How this test works
eGFR is adjusted to a standard body surface area, which is why the units include 1.73 m². Estimates are less precise in some people, especially when muscle mass differs substantially from average. Trends and other tests help resolve uncertainty.