eGFR: What Your Kidney Function Number Means

Updated June 2026

Last updated: June 2026 - Reviewed by the Apexzen editorial team

Part of: Blood Biomarkers Guide

What is eGFR? Estimated glomerular filtration rate is a calculation, based on a blood creatinine test plus factors such as your age and sex, that estimates how many milliliters of blood your kidneys filter each minute. It is one of the main tools clinicians use to gauge kidney health. Because it is an estimate, it is interpreted over time and alongside other tests such as urine albumin, not from a single number alone.

Optimal and reference range

The figures below are typical lab reference ranges, which vary by lab and individual. Your own report's range is the one that counts. Discuss your results with your doctor or clinician.

Category Typical reference value Units
Normal kidney function about 90 or higher mL/min/1.73m2
Below normal (per doctor) under about 60 needs review mL/min/1.73m2

Ranges vary by lab and individual; discuss your results with your doctor.

What affects eGFR and what helps

Protecting kidney function is mostly about managing the conditions that strain it, under a clinician's guidance:

  • Keep blood pressure and blood sugar in your doctor's target ranges, since high levels are leading causes of kidney damage.
  • Stay well hydrated and follow a balanced, mostly whole-food diet.
  • Use over-the-counter pain relievers such as NSAIDs sparingly, as frequent use can stress the kidneys.
  • Avoid smoking and keep alcohol within sensible limits.

Temporary factors such as dehydration or a recent high-protein meal can also nudge a reading, which is another reason your doctor may repeat the test.

When to talk to your doctor

See your doctor if your eGFR is below your lab's range, if it has dropped compared with earlier results, or if you have diabetes, high blood pressure, or a family history of kidney disease. Your clinician can confirm the result, check a urine test, and decide whether monitoring or treatment is needed.

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Frequently asked questions

Is a low eGFR always serious?

Not necessarily. A single low reading can reflect dehydration, a recent meal, or lab variation. Your doctor looks at the trend and other tests before drawing conclusions.

Can eGFR improve?

It can stabilize or improve when reversible causes, such as dehydration or uncontrolled blood pressure, are addressed under medical care. Your doctor will guide what is realistic for you.

Should I take a supplement for my kidneys?

Do not start supplements for kidney function without medical advice. Some supplements can stress the kidneys. Talk to your doctor before taking anything if your eGFR is low.

Related reading: Uric Acid Levels Guide and Blood Biomarkers Guide.

Sources: National Institutes of Health (NIH); Centers for Disease Control and Prevention (CDC) - chronic kidney disease and kidney function guidance.

This article is for educational purposes only and is not medical advice. These statements have not been evaluated by the Food and Drug Administration. Apexzen products are not intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare provider before changing your diet, supplements, or treatment.

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