Content updated on September 7, 2021 - Medically reviewed by our Medical Advisory Committee

Please note: The American Kidney Fund (AKF) is committed to ensuring that every person receives health care that is fair, equitable and of the highest quality. The estimated glomerular filtration rate (eGFR) is an estimate of how well your kidneys are working. Currently the test considers your age, sex and race, among other things. A task force led by the National Kidney Foundation (NKF) and the American Society of Nephrology (ASN) has made recommendations to remove Black race as a factor in the eGFR calculation. The task force received input from patients, the community and kidney disease experts, including AKF’s Medical Advisory Committee, to reduce bias in kidney function testing. AKF is reviewing the NKF-ASN recommendations and will update its outreach and educational programs ongoing as additional information and evidence evolves.

What is eGFR?

eGFR (estimated glomerular filtration rate) is a measure of how well your kidneys are working. Your eGFR is an estimated number based on a blood test and your age, sex, body type and race. 

eGFR is considered a mostly reliable test for doctors to know how well your kidneys are working. However, the eGFR may not be accurate if you are younger than 18, pregnant, very overweight or very muscular. In addition, other tests such as  an ultrasound or a kidney biopsy may be ordered to find a cause of your kidney disease.

How do I find out my eGFR?

You will have a blood test to see how much creatinine is in your blood. Creatinine is a waste product in your blood that comes from your muscles. Healthy kidneys take creatinine out of your blood and send it out of your body through your urine. If your kidneys are not working the way they should, creatinine will build up in your blood.

You will have a blood test to see how much creatinine is in your blood. Creatinine is a waste product in your blood that comes from your muscles. Healthy kidneys take creatinine out of your blood and send it out of your body through your urine. If your kidneys are not working the way they should, creatinine will build up in your blood.

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Can my eGFR change?

Your eGFR can change over time and can change based on some other problems, like if you have not been drinking enough water.

As chronic kidney disease gets worse, your eGFR number will go down. If caught early, healthy life changes like following a kidney-friendly eating plan and getting enough exercise may help slow down the progression of CKD and how fast your eGFR changes.

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Can I have kidney disease even if my eGFR is normal?

Yes, your eGFR may still be in the normal range even if you have some signs of kidney damage, such as protein in your urine (pee) or physical damage to your kidneys.

If you have protein in your urine, your doctor will check you again to make sure it is not caused by something else, like being dehydrated.

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Do I need to do anything to prepare for my eGFR test?

Your doctor may have you fast (not eat or drink) or avoid certain foods for several hours before the test. They will let you know how to prepare.

You may have a blood creatinine test as part of a regular check-up or if your doctor thinks you might have kidney disease. Your doctor will figure out your eGFR using your creatinine blood test result and your age, sex, weight and race.

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What does my eGFR mean?

A normal eGFR is 60 or more. If your eGFR is less than 60 for three months or more, your kidneys may not be working well. Use this chart to see what your eGFR may mean.

Stage 1 Stage 2 Stage 3 Stage 4 Stage 5

eGFR in normal range (greater than 90) with other signs of kidney damage, like protein in urine or physical damage to the kidneys

eGFR in normal range (60-89) with other signs of kidney damage, like protein in urine or physical damage to the kidneys

eGFR 30-59, moderate kidney damage

eGFR 15-29, severe kidney damage

eGFR less than 15, the kidneys are close to failure or have already failed

No matter what your eGFR is, take these steps to keep your kidneys as healthy as possible:

  • Keep a healthy blood pressure (less than 120/80 for most people).
  • Control your blood sugar if you have diabetes.
  • Follow a healthy low-salt, low-saturated-fat eating plan.
  • Do something active for at least 30 minutes most days of the week, such as walking or biking.
  • Keep a weight your doctor says is healthy for you.
  • Do not smoke or use tobacco.
  • Ask your doctor about medicines that may help protect your kidneys.

No matter what your eGFR is, ask your doctor when you should be tested again and what other tests you should have. Your doctor may want to do other tests to look for signs of kidney problems, such as:

  • Urine test for protein or blood
  • Blood test for other wastes
  • Blood pressure
  • Blood sugar (glucose) test

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