Plasma Creatinine (Creatinine Concentration)

Why This Test Matters

Creatinine is a byproduct of muscle breakdown and is normally filtered out of your blood by your kidneys. High levels can indicate poor kidney function, while low levels might suggest overhydration or other conditions. This test is often used alongside other measures to monitor 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 this test. You may have a small needle inserted into your arm or a tube placed in your vein to draw blood. If you’re on a low-protein diet or have recently exercised, your doctor may advise timing your test to avoid temporary fluctuations in results.

How the Test Works

Blood is drawn and sent to a lab, where it’s analyzed to measure creatinine concentration. The test uses a method called **nephelometry** or **enzymatic assay** to detect the substance. Results are compared to a reference range to assess kidney function.

Possible Results and What They Mean

Results may vary based on factors like muscle mass, hydration status, and overall health. Elevated creatinine levels may signal kidney damage, while persistently low levels could warrant further investigation. Your doctor will interpret results in the context of your medical history and other tests.