Creatinine Clearance (Calculated)

Why This Test Matters

Creatinine clearance is a key indicator of kidney function because creatinine is a waste product naturally produced in the body. Healthy kidneys efficiently filter it out. This test helps doctors monitor kidney health, especially in people with diabetes, high blood pressure, or other conditions that may affect the kidneys.

How the Test Works

Your doctor will likely order a 24-hour urine collection to measure how much creatinine is excreted over time. Blood is also drawn to determine your creatinine levels. The test calculates clearance by comparing these values to your body size and urine flow.

When You Might Need It

You may need this test if you have symptoms like fatigue, swelling, or frequent urination, or if you have a condition like diabetes, high blood pressure, or a family history of kidney disease. Doctors also use it to check kidney function before surgeries or during treatments for chronic illnesses.

What to Expect

For the urine test, you’ll collect all urine for 24 hours in a special container. For the blood test, a small needle is used to draw blood from a vein in your arm. Both tests are quick and usually painless, though you might feel a brief pinch.