Serum or Plasma Creatinine Concentration (Substance Concentration)

Why This Test Matters

Your kidneys normally filter waste products from your blood, including creatinine. If your kidneys aren’t working well, creatinine levels in your blood may rise. This test helps doctors monitor kidney health, especially if you have conditions like diabetes, high blood pressure, or a history of kidney problems.

What to Expect Before the Test

You may have this test done by drawing blood from a vein in your arm. If testing urine creatinine is needed, you’ll collect a sample in a container at home or during a clinic visit. Avoid excessive exercise or heavy meals 24 hours before blood testing to get accurate results.

How the Test Works

Blood creatinine levels are measured using a lab technique that detects the substance’s concentration. Urine creatinine tests check how much creatinine passes through your urine over a set period (often 24 hours). This helps determine how well your kidneys are filtering waste.

What the Results Mean

Higher than expected creatinine levels may suggest kidney problems, while lower levels could indicate dehydration or muscle loss. Your doctor will compare your results to your age, sex, and overall health to interpret them correctly.