Serum or Plasma Creatinine Concentration (Quantitative)

What Does This Test Measure?

Creatinine is a byproduct of muscle breakdown and is normally filtered out by your kidneys. Elevated levels may suggest impaired kidney function, while lower levels could indicate overhydration or other conditions. This test is often used alongside other measures like blood urea nitrogen (BUN) to evaluate kidney performance.

Why Is This Test Done?

Doctors order creatinine tests to monitor kidney health, especially in people with risk factors like diabetes, high blood pressure, or a family history of kidney disease. It may also be used before surgeries, during pregnancy, or to check for kidney issues after an injury or illness.

How Is the Test Performed?

A blood sample is taken from a vein in your arm. The sample is sent to a lab where it is analyzed to measure creatinine concentration using an automated method, often enzymatic or spectrophotometric. No special preparation is needed, but fasting may be advised in some cases.

What Are Common Results?

Results are typically reported in milligrams per deciliter (mg/dL) or micromoles per liter (µmol/L). While exact reference ranges vary by lab, higher than expected levels may indicate kidney problems, while very low levels may need further investigation.