eGFR
Estimated Glomerular Filtration Rate
What this test measures
eGFR shows how well your kidneys are working. Your kidneys filter waste from your blood. This test estimates how much blood your kidneys can clean each minute. It is calculated from a blood test called creatinine, along with your age and sex.
Understanding the numbers
Typical range: 90 or above (mL/min/1.73m²)
60-89 may be normal for some people, especially older adults. Below 60 for 3 months or more may mean chronic kidney disease.
- Stage 5 (severe): 0–15 mL/min/1.73m²
- Stage 4: 15–30 mL/min/1.73m²
- Stage 3b: 30–45 mL/min/1.73m²
- Stage 3a: 45–60 mL/min/1.73m²
- Stage 2: 60–90 mL/min/1.73m²
- Stage 1 (normal): 90–120 mL/min/1.73m²
Key numbers
- 60 mL/min/1.73m² — Below = CKD if persistent for 3 months
- 30 mL/min/1.73m² — Consider specialist referral
- 15 mL/min/1.73m² — Severe — preparation for kidney replacement
- 45 mL/min/1.73m² — CKD 3b — tighter monitoring and medication review
Bands follow the KDIGO / NICE NG203 staging for chronic kidney disease. Diagnosis of CKD requires the eGFR to be below 60 (or markers of kidney damage) persistently for at least three months. A single low eGFR is not enough on its own.
Ranges can vary slightly between laboratories — your report may show slightly different numbers. This page does not read or interpret your result; your GP looks at it alongside your history and other tests.
What a higher-than-normal result can mean
- A high eGFR is usually not a concern
- It means your kidneys are filtering blood well
- Very high levels are rare and usually not clinically significant
When not to wait
A sudden big drop in kidney function is an emergency. If you have known kidney disease and feel very unwell, or cannot keep fluids down, don't wait.
- Passing very little or no urine over a day
- Vomiting repeatedly or unable to keep water down
- Swollen ankles or breathlessness at rest
- Feeling drowsy, confused, or very weak
- Chest pain or a racing heart
- Known CKD with a new severe illness or diarrhoea/vomiting
Call NHS 111 for urgent advice, or 999 if someone is seriously unwell.
Questions you could ask your GP
- What stage of kidney function does my result suggest?
- How often should I have my kidney function monitored?
- Are any of my current medicines affecting my kidneys?
- Should I be referred to a kidney specialist?
Example stories
These are made-up examples to show how results are talked about in real appointments. They are not real patients.
New-job medical
James had his first full health check for a new job. His eGFR was 102 — comfortably in the normal range.
What the GP said: “Your kidneys are working well. No action needed. We'll only recheck if anything changes or if you develop high blood pressure or diabetes.”
A one-off normal eGFR in a younger adult is reassuring. eGFR naturally falls a little with age — a result of 85 in a 70-year-old is not the same as 85 in a 30-year-old.
Hypertension review
Meena has had high blood pressure for 15 years. Her eGFR has been around 55-60 for three years, and today it was 52. A urine test showed no protein.
What the GP said: “This is stable mild chronic kidney disease, stage 3a. At your age this can be a long, slow process — what we need to do is protect the kidneys you have: keep your blood pressure tight, avoid ibuprofen, and check yearly.”
What happened next: Meena's ramipril dose was adjusted, she was started on atorvastatin, and a yearly CKD review was booked. Her eGFR stayed around 50-55 over the next five years.
CKD stage 3a in an older adult is very common and often doesn't progress quickly. Treatment is about slowing the decline — blood pressure control, avoiding kidney-toxic medicines (like regular ibuprofen), and annual review.
Diabetes — slipping kidney function
Arjun has had Type 2 diabetes for 12 years. His eGFR was 38 mL/min/1.73m² and his urine ACR was 18 mg/mmol — showing protein.
What the GP said: “This is CKD stage 3b with protein in the urine. In diabetes this combination raises the urgency. I'd like to start you on an SGLT2 inhibitor like dapagliflozin — it protects the kidneys — and refer you to the kidney clinic.”
What happened next: Arjun was started on dapagliflozin and his ACR fell to 8 mg/mmol over six months. His eGFR stabilised around 36-40.
Diabetes plus protein in the urine plus reduced eGFR is a combination that needs active treatment, not just monitoring. Newer medicines (SGLT2 inhibitors) slow kidney decline substantially.
Acute drop during a vomiting illness
Patrick's baseline eGFR was 55. After three days of a vomiting illness, a repeat blood test showed eGFR 28 — a sharp drop.
What the GP said: “This is an acute kidney injury on top of your background kidney disease. Dehydration is the trigger, and some of your medicines are making it worse. Stop the ramipril and the diclofenac today, get fluids in, and come back in 48 hours for a repeat blood test.”
What happened next: Patrick rehydrated, stopped the two medicines, and his eGFR was back to 52 within a week. His ramipril was restarted after his blood tests confirmed recovery.
A sudden drop in eGFR during illness is acute kidney injury (AKI). It is often reversible if caught early. The 'sick day' rule — pause ACE inhibitors, diuretics and NSAIDs if you can't keep fluids down — is something to know if you have CKD, diabetes or heart failure.
Before you act on anything here
This page is general information, written to help you understand — it is not personal medical advice and it cannot tell you what is right for you. Talk to your own GP, pharmacist or nurse about your own health.
- Need help now but it's not an emergency? Call NHS 111 or use 111.nhs.uk.
- Emergency? Call 999 or go to A&E.