Urine Test Family

Our next five lab tests also measure wastes, but they do it using a urine sample instead of a blood sample. For this reason, they are more likely to be done in people whose failing kidneys have reached CKD stage 4 or early stage 5, but do not need dialysis yet. (People with kidney failure usually make little or no urine.) We'll call these lab tests the urine test family. They are:

• Urine blood or urine hemoglobin (Heme)
• Creatinine clearance
• Urine albumin
• Microalbuminuria
• Albumin-to-creatinine ratio

Urine hemoglobin is a test to see if there is blood or hemoglobin in the urine. There should not be any blood in the urine, so finding blood can mean damage to the kidneys or urinary tract. Heavy smoking, jogging, bladder infections, and other causes can lead to blood in the urine, too.

A creatinine clearance test shows how fast your kidneys remove creatinine from your blood.

To measure creatinine clearance you must collect urine for a 24-hour period. All of your urine is saved in a special container.

When you take the urine container to the lab, they will take a blood sample. Having both a urine and a blood sample lets your doctor compare how much creatinine your body is making—and how much your kidneys are removing.

The creatinine clearance test gives your doctor a good measure of how well your kidneys are working.