Serum Creatinine (with optional 24-hour urine collection for creatinine clearance calculation)

Why This Test Matters

Creatinine is a byproduct of muscle breakdown and is naturally filtered out by your kidneys. High levels can signal kidney problems, while low levels may indicate dehydration or other conditions. This test is often used alongside other kidney function tests to monitor overall kidney health, especially in people with diabetes, high blood pressure, or a family history of kidney disease.

What to Expect Before the Test

No special preparation is needed for a basic blood creatinine test. For a 24-hour urine creatinine test, you’ll need to collect all urine over 24 hours in a special container. Your healthcare provider will guide you through the process to ensure accuracy.

Common Reasons for Testing

Doctors may order a creatinine test to check for kidney disease, evaluate kidney function before surgery, monitor chronic conditions like diabetes or high blood pressure, or assess hydration status. It’s also used to monitor treatment effectiveness for conditions affecting the kidneys.

What the Results Mean

Results are typically compared to a reference range provided by your lab. While exact values can vary by lab, higher creatinine levels may indicate reduced kidney function, while lower levels might suggest dehydration or other metabolic issues. Your doctor will interpret results in the context of your overall health and medical history.