24-Hour Creatinine Clearance (from urine)

What Does This Test Measure?

Creatinine is a waste product from muscle metabolism that kidneys normally remove from your blood. This test evaluates how efficiently your kidneys clear creatinine from your body by collecting all urine produced in 24 hours and measuring its concentration. The result helps determine kidney function and detect early signs of kidney disease.

Why Is This Test Done?

Your healthcare provider may order this test if you have symptoms of kidney problems, such as swelling, fatigue, or changes in urine output. It’s also used to monitor kidney function in people with diabetes, high blood pressure, or other conditions that can affect kidney health.

How Is This Test Performed?

You’ll need to collect all urine for a full 24-hour period in a special container. Typically, you’ll start the collection in the morning after emptying your bladder, then continue collecting every time you urinate until the next morning. The urine is then sent to the lab for analysis.

What Are Possible Results?

Results are expressed as a clearance rate (e.g., milliliters per minute or milliliters per hour), which compares your creatinine clearance to a healthy range. While exact reference ranges vary by lab, lower than expected clearance may indicate kidney damage or dysfunction.