UK kidney health guideeGFR Explained for UK Patients: What the Kidney Function Number Means
eGFR stands for estimated glomerular filtration rate. It is a calculation used to estimate how well the kidneys are filtering blood. It is commonly reported alongside a creatinine blood test.
Have a result to hand? Use our free eGFR calculator to estimate your eGFR from your creatinine (µmol/L), age and sex.
An eGFR result is useful, but it is not a complete description of kidney health. Doctors consider the result together with previous measurements, urine tests, symptoms, age, medical history and other findings.
eGFR categories
Broadly, an eGFR of 90 or above is usually considered within the normal or high range, although other evidence of kidney damage can still matter. Lower values can indicate reduced kidney function. CKD classification also considers whether reduced function is persistent and whether there is evidence of kidney damage such as albumin in the urine.
An isolated eGFR result should therefore not automatically be interpreted as a diagnosis.
Why can eGFR change?
eGFR can change because of biological variation, hydration status, acute illness, medications and changes in creatinine. A single result may need to be repeated before conclusions are made.
eGFR and CKD stages
CKD staging commonly uses eGFR categories together with evidence of kidney damage. Stage 3 is generally divided into G3a and G3b. Stages 4 and 5 represent more severe reductions in kidney function.
Your healthcare professional can explain how your current result compares with previous results.
What should you do with an abnormal result?
Ask what your eGFR means in the context of your urine ACR, blood pressure and previous tests. If you have diabetes, high blood pressure or another condition that can affect the kidneys, regular monitoring may be particularly important.
Nisarg Ayurveda provides educational resources and complementary consultation support. Ayurvedic consultation should not replace investigation or treatment recommended by your GP or kidney specialist.
eGFR results by value: 15 to 90
Looking for a specific eGFR number from a recent test? These quick reference entries explain which CKD stage each value falls into. They are educational only and do not replace advice from your GP or kidney specialist.
What does eGFR 15 mean?
An eGFR of 15 falls within CKD stage G4 on standard UK kidney-function categories. This value is the lower boundary of CKD stage 4 (severe reduction in kidney function). At this level, specialist nephrology input and closer monitoring are typically already in place. As always, a single number should be interpreted alongside previous results, urine tests and your overall clinical picture — discuss your specific result with your GP or kidney specialist.
What does eGFR 20 mean?
An eGFR of 20 falls within CKD stage G4 on standard UK kidney-function categories. This value is within CKD stage 4 (severe reduction). Clinicians usually focus on slowing further decline, managing complications, and planning ahead for possible future treatment options. As always, a single number should be interpreted alongside previous results, urine tests and your overall clinical picture — discuss your specific result with your GP or kidney specialist.
What does eGFR 25 mean?
An eGFR of 25 falls within CKD stage G4 on standard UK kidney-function categories. This value is within CKD stage 4, in the upper part of that range. Regular monitoring and management of related factors such as blood pressure are common at this stage. As always, a single number should be interpreted alongside previous results, urine tests and your overall clinical picture — discuss your specific result with your GP or kidney specialist.
What does eGFR 30 mean?
An eGFR of 30 falls within CKD stage G3b on standard UK kidney-function categories. This value is the lower boundary of CKD stage 3b (moderate-to-severe reduction). This is often when monitoring frequency increases and specialist referral may be considered, depending on other findings. As always, a single number should be interpreted alongside previous results, urine tests and your overall clinical picture — discuss your specific result with your GP or kidney specialist.
What does eGFR 35 mean?
An eGFR of 35 falls within CKD stage G3b on standard UK kidney-function categories. This value is within CKD stage 3b. Alongside the eGFR number, clinicians look at trends over time and urine albumin results to judge how the kidneys are functioning overall. As always, a single number should be interpreted alongside previous results, urine tests and your overall clinical picture — discuss your specific result with your GP or kidney specialist.
What does eGFR 40 mean?
An eGFR of 40 falls within CKD stage G3b on standard UK kidney-function categories. This value is within CKD stage 3b, towards its upper end. Many people at this level are managed by their GP with periodic kidney function checks. As always, a single number should be interpreted alongside previous results, urine tests and your overall clinical picture — discuss your specific result with your GP or kidney specialist.
What does eGFR 45 mean?
An eGFR of 45 falls within CKD stage G3a on standard UK kidney-function categories. This value is the lower boundary of CKD stage 3a (mild-to-moderate reduction). This range is common and does not by itself indicate an emergency, but ongoing monitoring is usual. As always, a single number should be interpreted alongside previous results, urine tests and your overall clinical picture — discuss your specific result with your GP or kidney specialist.
What does eGFR 50 mean?
An eGFR of 50 falls within CKD stage G3a on standard UK kidney-function categories. This value is within CKD stage 3a. As with any single result, it should be read alongside previous values, blood pressure, and any urine albumin (ACR) results. As always, a single number should be interpreted alongside previous results, urine tests and your overall clinical picture — discuss your specific result with your GP or kidney specialist.
What does eGFR 55 mean?
An eGFR of 55 falls within CKD stage G3a on standard UK kidney-function categories. This value is within CKD stage 3a, towards its upper end. Many people remain stable at this level for a long time with routine monitoring. As always, a single number should be interpreted alongside previous results, urine tests and your overall clinical picture — discuss your specific result with your GP or kidney specialist.
What does eGFR 60 mean?
An eGFR of 60 falls within CKD stage G2 on standard UK kidney-function categories. This value is the lower boundary of CKD stage 2 (mild reduction). On its own, an eGFR of 60 is often not diagnostic of CKD unless there is other evidence of kidney damage. As always, a single number should be interpreted alongside previous results, urine tests and your overall clinical picture — discuss your specific result with your GP or kidney specialist.
What does eGFR 65 mean?
An eGFR of 65 falls within CKD stage G2 on standard UK kidney-function categories. This value is within CKD stage 2 (mild reduction). This is frequently seen and, without other markers of kidney damage, may simply reflect normal age-related variation. As always, a single number should be interpreted alongside previous results, urine tests and your overall clinical picture — discuss your specific result with your GP or kidney specialist.
What does eGFR 70 mean?
An eGFR of 70 falls within CKD stage G2 on standard UK kidney-function categories. This value is within CKD stage 2. Clinicians typically look at trend over time rather than a single reading at this level. As always, a single number should be interpreted alongside previous results, urine tests and your overall clinical picture — discuss your specific result with your GP or kidney specialist.
What does eGFR 75 mean?
An eGFR of 75 falls within CKD stage G2 on standard UK kidney-function categories. This value is within CKD stage 2, and often not a cause for concern on its own, particularly without other abnormal kidney test results. As always, a single number should be interpreted alongside previous results, urine tests and your overall clinical picture — discuss your specific result with your GP or kidney specialist.
What does eGFR 80 mean?
An eGFR of 80 falls within CKD stage G2 on standard UK kidney-function categories. This value is within CKD stage 2, towards the higher end. This is a common result and, in isolation, is not usually a sign of a problem. As always, a single number should be interpreted alongside previous results, urine tests and your overall clinical picture — discuss your specific result with your GP or kidney specialist.
What does eGFR 85 mean?
An eGFR of 85 falls within CKD stage G2 on standard UK kidney-function categories. This value is within CKD stage 2, close to the normal range. Age, muscle mass and hydration can all influence where an individual result falls. As always, a single number should be interpreted alongside previous results, urine tests and your overall clinical picture — discuss your specific result with your GP or kidney specialist.
What does eGFR 90 mean?
An eGFR of 90 falls within CKD stage G1 on standard UK kidney-function categories. This value is generally considered within the normal-to-high range (CKD stage 1 territory), though a diagnosis of CKD at this level would depend on other evidence of kidney damage, such as protein in the urine. As always, a single number should be interpreted alongside previous results, urine tests and your overall clinical picture — discuss your specific result with your GP or kidney specialist.
Want to discuss your situation?
Nisarg Ayurveda offers complementary Ayurvedic consultation support. Bring your relevant medical reports and medication list to the consultation. This service does not replace GP, nephrology or emergency care.