Healthcare providers use estimated glomerular filtration rate (eGFR) to determine if you have kidney damage and stage kidney disease. eGFR measures your kidneys’ ability to filter toxins from your blood. A low number may indicate kidney failure, which means you need dialysis or a kidney transplant.
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Estimated glomerular filtration rate (eGFR) is an estimated calculation of how well your kidneys work. It’s based on a blood test that measures the creatinine (or cystatin C). Your kidneys contain glomeruli. Glomeruli are groups of tiny blood vessels that help remove toxins (waste) from your blood. Your eGFR measures how well the blood is cleaned by the glomeruli in 1 minute.
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Your estimated glomerular filtration rate helps healthcare providers spot problems with your kidneys, including chronic kidney disease (CKD). When you have CKD, your glomeruli aren’t filtering the blood appropriately. That causes dangerous toxins to build up in your blood.
When you have a blood test as part of a routine checkup, eGFR is often part of the basic metabolic panel. A healthcare provider may also check your eGFR to help determine if you have chronic kidney disease and, if you do, how severe it is.
A provider may also use your eGFR to monitor your kidney health if you have or take medications to treat the following:
Healthcare providers use a formula to estimate your glomerular filtration rate. They calculate your eGFR value from the serum (blood) creatinine or cystatin C in your blood sample, along with your:
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Your body makes and uses creatine to provide energy to your muscles. When your muscles use this energy, the muscle tissue breaks down and the creatine turns into creatinine, which gets into your blood. Healthy kidneys filter creatinine out of your blood, and your body gets rid of it when you urinate (pee). If you have CKD, creatinine stays in your blood and may gradually build up.
Providers sometimes measure cystatin C levels in your blood if your creatinine results aren’t conclusive. Cystatin C is a small protein that your body’s cells make. Your age, muscle mass and/or diet may affect your creatinine levels. But these factors don’t affect your cystatin C levels. If you’re over 65 or have a lot of muscle mass, your cystatin C levels may more accurately indicate your kidney function than your creatinine levels.
An eGFR blood test is very sensitive, especially for a creatinine blood test. You may not get an accurate eGFR if you don’t follow the healthcare provider’s guidelines to prepare for the test. These may involve:
You may not get an accurate eGFR if you don’t follow the provider’s guidelines.
eGFR is usually part of a routine blood test. A healthcare provider typically draws blood from a vein in your arm. They then send your blood sample to a lab for analysis.
Let the provider know if you’re afraid of needles. They can suggest ways to help you relax before taking your blood sample
After taking your blood sample, the provider will put a bandage on the spot where the needle went in. They may suggest that you rest for a few minutes before you stand up and leave. Once they determine you’re OK, you can go home.
An eGFR blood test is very safe. Common side effects include:
There’s also a small chance of:
For adults, a normal eGFR is about 100. The lowest eGFR is 0, which means your kidneys aren’t working. A healthcare provider may diagnose chronic kidney disease if your eGFR stays below 60 for three months.
Your eGFR will decrease as you age, even if you don’t have kidney disease. The chart below indicates a normal range for eGFR according to your age.
Age (Years) | Average Estimated Glomerular Filtration Rage (eGFR) |
---|---|
20-29 | 116 |
30-39 | 107 |
40-49 | 99 |
50-59 | 93 |
60-69 | 85 |
70 and over | 75 |
Age (Years) | |
20-29 | |
Average Estimated Glomerular Filtration Rage (eGFR) | |
116 | |
30-39 | |
Average Estimated Glomerular Filtration Rage (eGFR) | |
107 | |
40-49 | |
Average Estimated Glomerular Filtration Rage (eGFR) | |
99 | |
50-59 | |
Average Estimated Glomerular Filtration Rage (eGFR) | |
93 | |
60-69 | |
Average Estimated Glomerular Filtration Rage (eGFR) | |
85 | |
70 and over | |
Average Estimated Glomerular Filtration Rage (eGFR) | |
75 |
There are five stages of chronic kidney disease. Stage V CKD is a sign of kidney failure.
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You should get the results of an eGFR blood a few days after your blood draw.
A healthcare provider may recommend additional tests if your eGFR blood test results are abnormal. These may include:
Call a healthcare provider if you have kidney disease or risk factors, such as:
You likely have chronic kidney disease if you’ve had an eGFR of 60 or lower for more than three months. You may also have CKD if your eGFR is above 60 and you have signs of kidney damage.
It depends on your age and other factors. A mildly low eGFR doesn’t definitively mean you have kidney disease. But having a healthcare provider check your eGFR regularly is a good idea.
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eGFR gives a general estimate as to how well your kidneys work. Healthcare providers can precisely measure your glomerular filtration rate, but the tests are complex. Because of this, providers typically only use measured glomerular filtration rate (mGFR) for research or kidney transplant purposes.
It’s important for a healthcare provider to monitor your estimated glomerular filtration rate if you’re at risk of kidney disease or already have it. It’s also a good idea to pay attention to your eGFR if you take medications that increase your risk of kidney disease. If your eGFR indicates kidney disease, you can take steps to protect your kidneys from further damage.
Certain medications, maintaining a healthy weight for you, regular exercise and changes to what you eat can help your kidney health. If you have any questions, reach out to a provider.
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If you have a condition that’s affecting your kidneys, you want experts by your side. At Cleveland Clinic, we’ll work with you to craft a personalized treatment plan.
Last reviewed on 05/28/2025.
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