The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and other professional health organizations help raise awareness for kidney health every March. This post provides helpful information on the kidneys and different ways to get tested for kidney disease.
General Information About the Kidneys
The kidneys are two bean-shaped organs, each about the size of a fist. They are located just below the rib cage, one on each side of your spine.
Healthy kidneys filter about a half cup of blood every minute, removing wastes and extra water to make urine. The urine flows from the kidneys to the bladder through two thin tubes of muscle called ureters, one on each side of your bladder. Your bladder stores urine. Your kidneys, ureters, and bladder are part of your urinary tract.
Why Are the Kidneys Important?
Your kidneys remove wastes and extra fluid from your body. Your kidneys also remove acid that is produced by the cells of your body and maintain a healthy balance of water, salts, and minerals—such as sodium, calcium, phosphorus, and potassium—in your blood.
Without this balance, nerves, muscles, and other tissues in your body may not work normally.
Your kidneys also make hormones that help:
- control your blood pressure
- make red blood cells
- keep your bones strong and healthy
What Tests Do Doctors Use to Diagnose and Monitor Kidney Disease?
To check for kidney disease, health care providers use:
- a blood test that checks how well your kidneys are filtering your blood, called GFR. GFR stands for glomerular filtration rate.
- a urine test to check for albumin. Albumin is a protein that can pass into the urine when the kidneys are damaged.
If you have kidney disease, your health care provider will use the same two tests to help monitor your kidney disease and make sure your treatment plan is working.
Blood Test for GFR
Your health care provider will use a blood test to check your kidney function. The results of the test mean the following:
- a GFR of 60 or more is in the normal range. Ask your health care provider when your GFR should be checked again.
- a GFR of less than 60 may mean you have kidney disease. Talk with your health care provider about how to keep your kidney health at this level.
- a GFR of 15 or less is called kidney failure. Most people below this level need dialysis or a kidney transplant. Talk with your health care provider about your treatment options.
Urine Test for Albumin
If you are at risk for kidney disease, your provider may check your urine for albumin.
Albumin is a protein found in your blood. A healthy kidney doesn’t let albumin pass into the urine. A damaged kidney lets some albumin pass into the urine. The less albumin in your urine, the better. Having albumin in the urine is called albuminuria.
