Urinary Creatinine to Creatinine Clearance Ratio (24-hour urine)

Why This Test Is Done

Your healthcare provider may order this test if you have symptoms like swelling, frequent urination, or fatigue that could indicate kidney problems. It may also be used to monitor kidney function in people with diabetes, high blood pressure, or other chronic conditions affecting the kidneys.

How the Test Works

You’ll collect all your urine for a full 24-hour period in a special container. Blood will also be drawn from a vein in your arm. The urine and blood samples are then sent to a lab to measure creatinine levels. The ratio helps determine how efficiently your kidneys are removing waste.

Sample Collection Process

For the urine sample, start collecting every time you urinate—including first morning urine—into the container. Replace the lid between collections. For the blood draw, a healthcare provider will insert a needle into your vein to take a small blood sample.

What to Expect Before the Test

No special preparation is needed for this test. However, you may be asked to drink extra fluids the day before if your urine volume is unclear. Avoid certain medications that could affect kidney function, but always check with your provider first.