Kidney Tests

You have two kidneys. They are fist-sized organs on either side of your backbone above your waist. Your kidneys filter and clean your blood, taking out waste products and making urine. Kidney tests check to see how well your kidneys are working. They include blood, urine, and imaging tests.

Early kidney disease usually does not have signs or symptoms. Testing is the only way to know how your kidneys are doing. It is important for you to get checked for kidney disease if you have the key risk factors - diabetes, high blood pressure, heart disease, or a family history of kidney failure.

Specific kidney tests include:

• Glomerular filtration rate (GFR) - one of the most common blood tests to check for chronic kidney disease. It tells how well your kidneys are filtering.
• Creatinine blood and urine tests - check the levels of creatinine, a waste product that your kidneys remove from your blood
• Albumin urine test - checks for albumin, a protein that can pass into the urine if the kidneys are damaged
• Imaging tests, such as an ultrasound - provide pictures of the kidneys. The pictures help the health care provider see the size and shape of the kidneys, and check for anything unusual.
• Kidney biopsy - a procedure that involves taking a small piece of kidney tissue for examination with a microscope. It checks for the cause of kidney disease and how damaged your kidneys are.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases