Serum or Plasma Creatinine Concentration (Mass Concentration)

Why This Test Matters

Creatinine is a byproduct of muscle breakdown and is normally filtered out of your blood by your kidneys. If your kidneys aren’t working well, creatinine builds up in your blood. Measuring it helps determine how effectively your kidneys are functioning and can indicate early kidney problems.

How the Test Works

Blood is drawn from a vein, usually in your arm. The sample is sent to a lab where it’s analyzed to measure creatinine levels using a specialized test method. The result is compared to a reference range to assess kidney function.

What to Expect Before the Test

You can eat and drink normally before the test, as creatinine levels don’t change significantly with food or hydration unless you’re being monitored closely for kidney function. Avoid excessive alcohol or contrast dyes (if prescribed) before the test, as they may affect results.

What to Expect During the Test

The test involves a quick blood draw, typically done by a healthcare professional. You may feel a slight pinch, but it usually takes only a few seconds. The blood sample is then processed and sent to the lab for analysis.