Serum or Plasma Creatinine Concentration (Standard Method)

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 properly, creatinine levels can build up in your blood. This test helps doctors monitor kidney health, especially in people with conditions like diabetes, high blood pressure, or chronic kidney disease.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to avoid certain medications or foods that could affect results (like supplements containing creatinine or certain vitamins). If you have a recent kidney procedure, your doctor may advise timing your test carefully.

How the Test Works

A small blood sample is taken from a vein in your arm. The sample is sent to a lab, where it’s analyzed to measure creatinine concentration using a standard laboratory method (often automated chemistry or spectrophotometry).

What the Results Mean

Results are typically reported in milligrams per deciliter (mg/dL) or micromoles per liter (µmol/L). Higher than expected levels may indicate kidney problems, while very low levels could suggest muscle disorders or liver disease. Your doctor will interpret results in relation to your overall health and medical history.