Serum or Plasma Creatinine Concentration (Mass Concentration)

Why This Test Matters

Creatinine is a natural byproduct of muscle metabolism and is filtered out of your blood by your kidneys. If your kidneys aren’t working well, creatinine levels can build up in your blood. This test helps doctors monitor kidney health, especially if you have conditions like diabetes, high blood pressure, or a history of kidney disease.

What to Expect Before the Test

You may be asked to fast for a few hours before the test, but this isn’t always required. Bring any medications you’re currently taking, as some may affect results. Avoid strenuous activity or heavy meals before testing.

How the Test Is Done

A healthcare provider will draw blood from a vein in your arm using a small needle. You may feel a slight pinch, but it usually doesn’t cause discomfort. The blood is then sent to a lab for analysis.

What the Results Mean

Results are compared to a reference range, which can vary slightly by lab. Higher levels may indicate poor kidney function, while lower levels might suggest overhydration or muscle loss. Your doctor will discuss your specific results in the context of your health.