Kidney Test: eGFR

Kidney Test: eGFR

Kidney disease often has no signs.  The only way to know how well your kidneys are working is to check them.  One way to do this is the eGFR test.

What is eGFR?
How can I get my eGFR?
Is there anyone this test won’t work for?
What does my eGFR mean?
More Information

What is eGFR?

Your kidneys filter your blood.  They remove wastes and water and make urine.  Your doctor can check how healthy your kidneys are.  He or she will do a blood test that measures how much blood they are filtering.  This test is called the eGFR (estimated glomerular filtration rate).

How can I get my eGFR?

Your doctor will test your blood for creatinine. Creatinine is a waste that comes from your muscles.  Your doctor will use your creatinine result, your age, your sex and your race to figure out your eGFR.  Your creatinine may vary from day to day.  For the best results, you might need your eGFR tested again in a few months.

Is there anyone that this test won’t work for?

Yes.  This test is very good, but it is not for everyone.  This test is NOT for you if you are:

▪ Younger than 18
▪ Older than 70
▪ Pregnant
▪ Very overweight
▪ Very muscular
▪ Have another serious illness

If any of these describe you, talk to your doctor about other tests.

What does my eGFR mean?

Use the chart below to see what your eGFR may mean.

Based on the National Kidney Disease Education Program’s Suggestions for Laboratories, available at www.nkdep.nih.gov/resources/laboratory_reporting.htm.

*If your eGFR was 60 or MORE…

Your doctor will look for other signs to make sure you don’t have early kidney disease.  Your doctor may also look at:

▪ Your urine (for blood or protein)
▪ Your blood (for wastes and toxins)
▪ Your blood pressure
▪ Your health history
▪ Your family’s health history

Help protect your kidneys by eating healthy, staying active and seeing your doctor regularly.

If your eGFR was LESS than 60…

Talk to your doctor soon.  If this was your first eGFR test, talk to your doctor about when you should be tested again.  Your doctor will watch to see if your eGFR is less than 60 for 3 months or more.

If your doctor tells you that you have chronic kidney disease you should:

▪ Control any diabetes
▪ Control any high blood pressure
▪ Control cholesterol
▪ Treat any health problems caused by kidney disease, like bone disease and anemia (not enough red blood cells)
▪ Don’t use tobacco
▪ Exercise most days of the week
▪ Talk to your doctor about your diet and medicines
▪ Order our brochure “Living Well with Chronic Kidney Disease”

If you are African American…

Your eGFR is calculated a little differently.  This is because African Americans have more muscle mass than other groups. 

Some doctors and labs do not use your race when finding your eGFR.  Ask your doctor or lab if they used your race when they did your eGFR.  If they did not, you will need to multiply your eGFR result by 1.2.

Example:

▪ Norma is a 58 year-old African American woman.
▪ Her doctor tells her that the lab did not use her race for her eGFR.
▪ Her lab results showed that her eGFR was 50.
▪ Norma uses a calculator to multiply the eGFR from her lab results by 1.2.

50 x 1.2 = 60
60 is Norma’s correct eGFR.

At her next visit, Norma will ask her doctor when she should be tested again.

Click here to order our fact sheet, "Know Your Blood Work: eGFR"

More Information

American Association of Kidney Patients
http://www.aakp.org/aakp-library/GFR/

National Institute of Diabetes and Digestive and Kidney Diseases
http://kidney.niddk.nih.gov/kudiseases/pubs/yourkidneys/index.htm

National Kidney Disease Education Program
http://www.nkdep.nih.gov/resources/glomerular_filtration_rate.htm
http://www.nkdep.nih.gov/professionals/gfr_calculators/index.htm

National Kidney Foundation
http://www.kidney.org/kidneydisease/ckd/knowGFR.cfm

Updated 2/11/08