Creatinine Clearance (24-hour urine collection)

Why It’s Done

Your doctor may order this test if they suspect kidney disease, monitor kidney function over time, or evaluate how well medications are being processed by your kidneys. It helps determine if your kidneys are working properly to remove waste and excess fluids from your blood.

How It’s Done

You’ll collect all urine for a full 24-hour period in a special container. The test involves measuring creatinine levels in your urine and comparing it to a blood sample taken at the start or end of the collection period. This helps calculate your creatinine clearance rate.

What to Expect

You’ll need to start and end the urine collection at the same time each day. Drink plenty of fluids to help produce urine consistently, but avoid excessive alcohol or caffeine, as they can affect results. Follow your healthcare provider’s instructions carefully to ensure accurate results.

Factors That Can Affect Results

Factors like dehydration, muscle mass, diet (especially protein intake), and certain medications can influence creatinine levels. Also, timing of blood and urine samples, as well as any recent illness or physical activity, may impact the test results.