eGFR stands for estimated glomerular filtration rate, and it is the best single number for how well your kidneys are filtering. Unlike creatinine — which depends on your muscle mass — eGFR is calculated from your creatinine together with your age and sex, which adjusts for those differences and gives a fairer picture of kidney function.
Think of eGFR as a percentage of normal filtering capacity: a value around 100 means your kidneys are doing roughly a full job, while lower numbers mean reduced filtering. It is reported in mL/min/1.73m². Crucially, eGFR works in the OPPOSITE direction to creatinine — a HIGH eGFR is good, a LOW eGFR signals reduced function.
eGFR stages (mL/min/1.73m²)
| Normal / Stage 1 | 90 or above | Healthy filtering (if no other kidney signs) |
|---|---|---|
| Stage 2 (mild) | 60 – 89 | Mild reduction — often age-related, usually monitored |
| Stage 3 (moderate) | 30 – 59 | Warrants medical review and monitoring |
| Stage 4 (severe) | 15 – 29 | Specialist kidney care needed |
| Stage 5 | Below 15 | Kidney failure — urgent specialist care |
A single eGFR in the 60–89 range is very common and often not disease — it must be repeated and seen in context. Compare to your own report.
What a low eGFR means
A low eGFR means your kidneys are filtering more slowly than expected. But the number alone does not equal kidney disease — context is everything. eGFR naturally declines with age, so an eGFR of 75 in a healthy 70-year-old may be completely normal for them. A mildly reduced eGFR (60–89) with no protein in the urine and no other abnormalities is frequently just normal variation or age, not illness.
Chronic kidney disease is defined not by a single low eGFR but by a reduced eGFR (or other kidney damage) that persists for at least three months. This is why one borderline result is never a diagnosis: doctors repeat it, check your urine for protein, and look at the trend. An eGFR that is stable over years is far more reassuring than a single low reading.
From decades of practice, the single most important thing to understand is that eGFR estimates can swing with hydration and the same temporary factors that affect creatinine. A low eGFR on a day you were dehydrated or had just exercised may rebound completely on a repeat test. Doctors act on the persistent trend, not the one-off.
What a high or normal eGFR means
An eGFR of 90 or above is generally normal and reassuring, indicating your kidneys are filtering well. Many labs simply report eGFR above 90 as '>90' rather than an exact figure, because the estimate is less precise at the high end — so don't read too much into whether it says 95 or 120. A high eGFR is not something to worry about. The only nuance is that in a person with very high muscle mass the estimate can read low even when kidneys are healthy, and rarely the reverse — which is why it's an estimate, confirmed by other tests when needed.
Why your eGFR changed since last time
Because eGFR is calculated from creatinine, anything that moves creatinine moves eGFR in the opposite direction — dehydration, a heavy protein meal, intense exercise, or certain medications can all lower eGFR temporarily. A drop from 95 to 82 between two routine tests is usually noise, not decline. What your doctor watches for is a sustained downward trend across several measurements, ideally taken under similar conditions. A stable eGFR, even one slightly below 90, is generally not a cause for concern on its own.
When to actually worry — and when not to
- eGFR below 60 that persists across repeated tests over three months or more — warrants medical review for chronic kidney disease.
- eGFR below 30 — needs specialist (nephrology) involvement.
- A steadily falling eGFR across several tests, even within the normal range — the trend matters; mention it to your doctor.
- A single eGFR of 60–89 with no other abnormalities — extremely common, often age-related, and usually not disease. It should be repeated, not panicked over.
- Low eGFR together with protein or blood in the urine — this combination is more meaningful than eGFR alone; show your doctor.
Common questions
Is an eGFR of 60 bad?
Not necessarily. An eGFR right around 60 is borderline and very common, especially with age. On its own — with no protein in the urine and a stable trend — it is often not disease. It's repeated and watched rather than treated as an automatic problem.
Can eGFR improve?
Yes, in many cases. If a low eGFR was caused by dehydration, a medication, or another reversible factor, it can rebound on a repeat test. Even in chronic kidney disease, controlling blood pressure and blood sugar can slow or stabilise decline.
Why is my eGFR low but I feel fine?
That's typical — reduced kidney filtration usually causes no symptoms until it is quite advanced, which is exactly why the blood test exists. Feeling well does not rule out a low eGFR, and a low eGFR does not mean you should feel unwell. The number guides monitoring.
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Upload your reportMedical disclaimer: This article is for educational and informational purposes only and does not constitute medical advice, diagnosis, or treatment. Reference ranges vary between laboratories — always compare your result to the range on your own report, and consult a qualified healthcare professional about your results and any symptoms.