A to Z Health Guide

Know Your Kidney Numbers: Two Simple Tests

Did you know one in three American adults is at risk for kidney disease? Anyone can get kidney disease at any time. If kidney disease is found and treated early, you can help slow or even stop it from getting worse. Most people with early kidney disease do not have symptoms. That is why it is important to be tested. Know your kidney numbers!

Your kidney numbers include 2 tests: ACR (Albumin to Creatinine Ratio) and GFR (glomerular filtration rate). GFR is a measure of kidney function and is performed through a blood test. Your GFR will determine what stage of kidney disease you have – there are 5 stages. Know your stage.ACR is a urine test to see how much albumin (a type of protein) is in your urine. Too much albumin in your urine is an early sign of kidney damage.

  • Urine Test called ACR. ACR stands for “albumin-to-creatinine ratio.” Your urine will be tested for albumin. Albumin is a type of protein. Your body needs protein. But it should be in the blood, not the urine. Having protein in your urine may mean that your kidneys are not filtering your blood well enough. This can be a sign of early kidney disease. If your urine test comes back “positive” for protein, the test should be repeated to confirm the results. Three positive results over three months or more is a sign of kidney disease.
  • Blood Test to estimate your GFR. Your blood will be tested for a waste product called creatinine. Creatinine comes from muscle tissue. When the kidneys are damaged, they have trouble removing creatinine from your blood. Testing for creatinine is only the first step. Next, your creatinine result is used in a math formula with your age, race, and sex to find out your glomerular filtration rate (GFR). Your GFR number tells your healthcare provider how well your kidneys are working. Check with your doctor about having a GFR test.

Here are some tips for talking with your doctor about your kidney health at your annual physical.

Date Reviewed: 
January 30, 2017

The information shared on our websites is information developed solely from internal experts on the subject matter, including medical advisory boards, who have developed guidelines for our patient content. This material does not constitute medical advice. It is intended for informational purposes only. No one associated with the National Kidney Foundation will answer medical questions via e-mail. Please consult a physician for specific treatment recommendations.