If your doctor said “your eGFR is 52, you have stage 3 CKD,” you probably nodded along and then googled the number when you got home. This guide explains what your eGFR result actually measures and how it decides your stage of kidney disease.
What eGFR Really Measures
eGFR stands for estimated Glomerular Filtration Rate. It estimates how much blood your kidneys filter every minute, which is the clearest single measure of your renal function.
A healthy adult kidney filters around 90 to 120 milliliters of blood per minute per 1.73 square meters of body surface area (mL/min/1.73 m²). When the tiny blood vessels inside your kidneys are damaged, they filter less, so your eGFR number drops.
You do not measure eGFR directly. It is calculated from three inputs pulled from a creatinine blood test:
- Your serum creatinine (a waste product from muscle activity)
- The person’s age
- The person’s sex
The math is built into most modern lab software. Your lab prints your eGFR result right next to your creatinine levels on the report.
If you need the test itself, you can book an eGFR test on NowServing.
A Note on Race Adjustment
Older equations used a race coefficient that adjusted results for Black patients. In 2021, the National Kidney Foundation and the American Society of Nephrology recommended replacing those older formulas with the race-free CKD-EPI 2021 equation.
KDIGO endorsed the same shift in its 2024 guideline. Philippine labs are moving to the race-free version, so your Filipino ancestry no longer changes the calculation.
Why eGFR Matters More Than Creatinine Alone
A 75-year-old woman and a 30-year-old man can both have a serum creatinine of 1.0 mg/dL. The man’s eGFR might be 95, which is completely normal. The woman’s eGFR might be 55, which places her in stage 3 CKD.
Raw creatinine levels do not account for how much muscle mass you carry, so they can hide real kidney trouble. Your eGFR result translates the same lab value into something meaningful for your body, and it is the number doctors use to assign your stage of kidney disease.
Learn more about creatinine and the normal levels of creatinine today!
How Your eGFR Decides Your CKD Stage
CKD staging follows KDIGO 2024, which sorts patients by eGFR (mL/min/1.73 m²). Your number places you in one of five stages:
| Stage | eGFR | What it means |
|---|---|---|
| 1 | 90 or above (with kidney damage signs) | Filtration is normal, but damage is present, usually a small amount of protein in the urine. |
| 2 | 60 to 89 (with kidney damage signs) | Mildly reduced filtration alongside the same damage markers. |
| 3a | 45 to 59 | Mild to moderate reduction in renal function. |
| 3b | 30 to 44 | Moderate to severe reduction. |
| 4 | 15 to 29 | Severe reduction. Planning for kidney replacement therapy usually begins. |
| 5 | Below 15 | Kidney failure. Dialysis or transplant is usually required. |
Stage 3 is split into 3a and 3b because outcomes and treatment intensity differ noticeably between the two.
For what each stage means for your treatment, monitoring, and day-to-day life, read our full guide to the 5 CKD stages.
The “Below 60 for 3 Months” Rule
A single low eGFR is not enough to diagnose CKD. Per KDIGO guidelines, chronic kidney disease is defined as either of the following, lasting three months or more:
- eGFR below 60 mL/min/1.73 m²
- Markers of kidney damage such as protein in urine, abnormal imaging, or biopsy findings, regardless of eGFR
So one bad lab result is not a diagnosis. Your doctor will repeat the test, order urine studies, and check for the underlying cause before staging you.
How Often eGFR Is Retested
Frequency depends on your stage of kidney disease and how stable your labs are.
- Stages 1 and 2: Yearly, more often if the underlying cause is not well controlled.
- Stage 3a: Every 6 months.
- Stage 3b: Every 3 to 6 months.
- Stage 4: Every 1 to 3 months.
- Stage 5: Monthly or more.
Discover how NSAIDs can affect you kidneys more in this guide.
Frequently Asked Questions
My eGFR went from 65 to 52 in one year. Should I be worried?
A drop of more than 5 mL/min in a year is faster than expected age-related decline. Talk to a nephrologist. The cause could be uncontrolled blood pressure, uncontrolled sugar, NSAID use, infection, or progression of the underlying kidney disease, and each needs a different response.
Can I have CKD with a normal eGFR?
Yes. Stages 1 and 2 count as CKD when signs of kidney damage are present, even though filtration looks normal. That is why a urine test for the amount of protein is part of every CKD workup.
My eGFR is 50 today and 65 next month. What is happening?
Your eGFR number fluctuates with hydration, recent meals, muscle mass changes, and lab variability. A single low value should be repeated before drawing conclusions. Look at the average trend over months, not one reading.
Does eGFR ever recover?
In acute kidney injury, yes, often substantially. In chronic kidney disease, usually not, but the rate of decline can be slowed dramatically with the right treatment plan and consistent disease control.
What is the difference between eGFR and creatinine clearance?
Creatinine clearance is calculated from a 24-hour urine collection, which is more accurate but inconvenient. eGFR is estimated from a single creatinine blood test plus the person’s age and sex, which is less precise but practical. For most patients, eGFR is good enough.
Talk to a Nephrologist About Your eGFR
If your last eGFR result was below 60, or if you have a family history of kidney disease and want a baseline check, a nephrologist can review your labs in a single online visit. Bring your latest creatinine blood test, urine test, and blood pressure readings so the doctor can stage you accurately.
