Kidney markers
High eGFR: Is a Result Over 90 Good?
Reviewed by a qualified clinician · analysed at UKAS-accredited UK labs (ISO 15189)
Last reviewed October 20265 min read
Every Helvy guide is written by our health editors, then checked by a qualified clinician before it goes live and re-checked as the science moves. We name clinical roles, not individuals, until each reviewer has agreed to be credited publicly. This is wellness guidance to help you understand your own data, not a diagnosis.
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An eGFR above 90 sits in the normal band, called G1. On its own it is not a kidney problem. Many UK labs simply print “>90” because the estimate gets less accurate as it climbs. A very high figure can reflect low muscle mass rather than unusually busy kidneys.
Not sure which markers you need? Build your test →Your report says eGFR 112, or just “>90”. Everything online is about low numbers. So is a high one good, bad, or nothing at all?
Mostly nothing at all. Here is why, and the few cases where it is worth a second look.
1. What does eGFR actually measure?
eGFR stands for estimated glomerular filtration rate. The glomeruli are the tiny filters in your kidneys. The rate is how much blood they clean each minute.
Nobody measures that directly on a routine test. The lab measures creatinine, a waste product from your muscles. A formula then turns creatinine, age and sex into an estimate. The unit is millilitres per minute, scaled to an average body size, written mL/min/1.73m².
That is why your result may not show a number at all. NICE asks labs to report eGFR as a whole number only up to 90, and as “greater than 90” above that. A 95 and a 125 can come back looking identical. Our eGFR blood test guide covers how the sum is built.
2. Is a high eGFR good or bad?
For most people it is simply normal. NICE groups kidney filtering into bands from G1 to G5. G1 covers 90 and over, and NICE labels it “normal and high”.
A G1 result only counts towards chronic kidney disease (CKD) when something else shows kidney damage. The usual sign is protein leaking into the urine. With no other marker, NICE’s own table reads “No CKD”.
So a higher number is not a higher score. 120 does not mean your kidneys are a third better than 90. Above 90, the figure stops carrying much extra meaning.
3. Why can the estimate read so high?
Because the formula is least sure of itself at the top end. NICE says so plainly:
“Interpret eGFR values of 60 ml/min/1.73 m² or more with caution, bearing in mind that estimates of GFR become less accurate as the true GFR increases.”
NICE guideline NG203, recommendation 1.1.7
The formula also assumes an average amount of muscle. Several ordinary things break that assumption:
- Less muscle. Less muscle makes less creatinine, and the formula reads that as faster filtering. NICE says reduced muscle mass leads to overestimation.
- Being young. Age is part of the sum, so younger adults tend to land higher.
- Pregnancy. NICE lists it among the times eGFR may be less reliable.
- Eating very little. NICE also names being malnourished on the same list.
There is one less common reason. In early diabetes the kidneys can work harder than usual, which researchers call hyperfiltration. A blood test cannot tell this apart from a normal high reading. If diabetes is a worry, that is a conversation for your GP.
4. Which numbers matter more than a high eGFR?
Three things tell you more than the eGFR itself.
- Your creatinine. The eGFR is built from it. A high eGFR usually sits beside a low creatinine. Our guide to low creatinine levels explains why that is rarely a worry.
- The trend. Above 90, NICE tells clinicians to watch creatinine instead. A rise of more than 20% is the signal they use.
- A urine test. The albumin to creatinine ratio, or ACR, checks for protein in your urine. It is the main way to spot kidney damage when eGFR looks normal. Your GP arranges it.
Our creatinine levels by age guide shows the usual spread. If your creatinine is the flagged number instead, see high creatinine levels.
5. What should you do about a high eGFR?
Usually nothing. A result above 90 with normal urea and salts is the expected picture for many adults. Our guide to urea and electrolytes results covers the rest of that report.
Keep the number for next time. A later result that drops sharply means more than any single high one. Being short of fluid can shift these markers too, as our guide to dehydration and blood test results explains.
Speak to a qualified clinician if you have diabetes or high blood pressure and have never had a urine ACR test. The same goes for swelling in your ankles, foamy urine, or blood in your urine. Those questions sit outside a blood test.
Your age changes the reading too. Our eGFR levels by age guide shows typical figures by decade, and low eGFR levels covers the other direction.
6. Which blood test reports eGFR?
Helvy’s Thyroid & Vital Organs panel reports eGFR beside creatinine and urea, with liver, thyroid and cholesterol markers. It is the only one of our panels that carries eGFR. It is a home finger-prick kit, processed by UKAS-accredited UK labs.
It does not include a urine ACR test. Our kidney function test guide explains how the blood and urine halves fit together.
Not sure which fits? The build-my-test tool walks you through it in about a minute.
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See eGFR, creatinine and urea on one report
Helvy’s home blood tests report the kidney markers as a set, so no single number has to carry the story alone. Samples are processed by UKAS-accredited UK labs.
Frequently asked questions
Is an eGFR over 90 normal?
Yes. NICE places 90 and over in band G1, described as normal and high. It only counts towards kidney disease if another sign of kidney damage is present, such as protein in the urine.
Why does my result just say >90?
NICE asks UK labs to report eGFR as a whole number up to 90 and as greater than 90 above that. The estimate gets less accurate as the true filtering rate rises.
Is an eGFR of 110 or 120 better than 90?
Not in any useful way. All three sit in the same normal band. Above 90 the formula is less precise, so a higher figure is not a higher grade of kidney health.
Can a high eGFR be a bad sign?
Rarely on its own. Low muscle mass is one reason a high estimate turns up. In early diabetes the kidneys can filter faster than usual, so if diabetes is a concern, ask your GP about a urine ACR test.
Does low muscle mass raise eGFR?
It can. Less muscle makes less creatinine, and the formula reads that as faster filtering. NICE notes that reduced muscle mass leads to an overestimate.
Should I retest a high eGFR?
Not because it is high. Keep it as a baseline. A clear fall on a later test, or a rising creatinine, is the change worth taking to a qualified clinician.
Related guides
eGFR Levels by Age UK
What the number usually reads at each decade.
Low eGFR Levels UK
The other direction, and what pulls it down.
eGFR Blood Test UK
How the estimate is made, and from what.
Low Creatinine Levels UK
The result that usually sits beside a high eGFR.
Kidney Function Test UK
What a full kidney check actually covers.
Creatinine Levels by Age UK
The marker the eGFR sum is built from.