24-Hour Urinary Creatinine Clearance

Why Is This Test Done?

Your doctor may order this test if they suspect kidney disease, poor kidney function, or if you have conditions like high blood pressure, diabetes, or heart disease that can affect kidney health. It’s also used to monitor kidney function in people with chronic kidney disease or after treatments that might impact kidney function.

What Does the Test Involve?

You’ll collect all your urine for a full 24-hour period in a special container. You’ll need to empty your bladder completely at the start and end of the period, discarding those samples. The test measures the amount of creatinine in your urine and compares it to a blood sample taken at the end of the period.

Sample Collection and Preparation

To ensure accurate results, follow your healthcare provider’s instructions carefully. Wear a bracelet or label your container with the date and time you start and finish collecting urine. Keep the container clean and refrigerate it if needed to prevent bacterial growth.

What Are the Results?

Results are typically reported as a clearance rate (e.g., in milliliters per minute or milliliters per hour). A lower clearance rate may indicate reduced kidney function, while a higher rate might suggest overhydration or other conditions. Your doctor will interpret the results in relation to your overall health and medical history.