Glossary term

eGFR

Also known as: Estimated Glomerular Filtration Rate, GFR

Part of: Kidney Function Tests

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3 min read
Last reviewed
Last reviewed January 1970
Reading level
Written in plain English
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Reviewed by Medipher Editorial Team

An estimate of how well your kidneys are filtering blood, calculated from your creatinine.

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Medipher explains medical wording in plain English — it does not diagnose or replace a clinician. If this is a medical emergency, call your local emergency number immediately.

Simple visual explanation

Blood reaches the kidneys
Filtered by nephrons
Creatinine measured
in the blood
eGFR calculated
Blood → kidneys → filtering → eGFR.

What is this?

eGFR stands for estimated Glomerular Filtration Rate — an estimate of how much blood your kidneys filter every minute.

It's calculated from your creatinine result together with your age and sex. It gives a clearer picture of kidney function than creatinine alone.

eGFR is an estimate, not a direct measurement. Small changes between tests are common and usually not significant.

It's reported as mL/min/1.73m² — a measurement adjusted for average adult body size.

Why is it important?

eGFR is the main number used to classify kidney health and to spot chronic kidney disease (CKD) early, before symptoms appear.

It's also used to check that medications processed by the kidneys are dosed safely.

Trends over months and years matter more than any single result. A stable eGFR is often reassuring, even if slightly reduced.

Where you'll see it: U&E blood test panels, alongside creatinine.

How doctors use this result

Clinicians may use this result to:

  • Classify kidney function and screen for chronic kidney disease.
  • Guide safe dosing of medications cleared by the kidneys.
  • Monitor conditions such as diabetes and high blood pressure that affect the kidneys.
  • Decide when to refer to a kidney specialist.

What's the normal range?

Normal≥ 90 mL/min/1.73m²
Mildly reduced60–89 mL/min/1.73m²
Moderately reduced30–59 mL/min/1.73m²
Severely reduced< 30 mL/min/1.73m²

An eGFR of 60–89 without other kidney abnormalities is common with age and is often not classed as kidney disease.

Kidney function slowly declines with age, so a value of 60–89 in an older adult without other kidney problems is often normal. Sudden drops are more meaningful than gradual, stable readings.

Normal ranges are guides, not verdicts. Interpretation depends on your age, sex, symptoms, medical history, medications and other investigations — which is why your clinician looks at the whole picture rather than a single value.

Common reasons it may be low

  • Reduced kidney function

    Damage to the filtering units of the kidney lowers eGFR — sometimes reversible, sometimes long-term.

  • Dehydration

    Reduces blood flow through the kidneys and drops eGFR temporarily.

  • Some medications

    Anti-inflammatories and certain other drugs can reduce eGFR while being taken.

  • Recent illness

    Infections and severe illness can temporarily impair kidney filtration.

  • Older age

    eGFR naturally decreases slowly over the decades.

Does an abnormal result always mean something is wrong?

Not necessarily. A number that sits outside the printed range is a prompt for interpretation — not a diagnosis.

  • A single result rarely gives the full picture — clinicians interpret it alongside your symptoms.
  • Your medical history, medications and other blood tests all shape the meaning of one value.
  • Small movements just outside the reference range are common and often not concerning.
  • Repeat testing over time is frequently more useful than any single number.

What might happen next?

  • A repeat eGFR after a few weeks to confirm the trend.
  • Urine tests looking for protein or blood.
  • Blood-pressure and blood-sugar checks.
  • Referral to a kidney specialist if the result is significantly reduced or falling.

One result rarely tells the whole story. Clinicians look at your symptoms, medical history, medications and other tests together — and a single value that sits slightly outside the reference range is often normal for you. Repeat testing over time is frequently more useful than any one number. Medipher helps you understand what a result means in plain English, but it cannot diagnose medical conditions or replace advice from a doctor, nurse or pharmacist.

When should I speak to a healthcare professional?

Speak with your GP or another healthcare professional if:

  • You've been asked to repeat the test.
  • You're experiencing new or worsening symptoms.
  • Your clinician has flagged the result as needing follow-up.
  • You don't understand your results or feel unsure what to do next.

If you have severe symptoms — chest pain, severe breathlessness, fainting, heavy bleeding or feel very unwell — seek urgent help. If this is a medical emergency, call your local emergency number immediately. Medipher is designed to help explain medical information and is not an emergency service.

Frequently asked questions

Related blood tests

Terms clinicians often look at alongside eGFR.

Related guides

Still unsure what your result means?

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Sources

General patient information referenced when writing this page.

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This glossary entry is general health information, not medical advice. Medipher explains medical wording in plain English and does not diagnose, provide treatment advice, or replace a GP, doctor, nurse or pharmacist. Always discuss your results with a qualified clinician.