Serum or Plasma Creatinine Concentration

What Does This Test Measure?

Creatinine is a waste product that your kidneys normally filter from your blood. High levels can indicate poor kidney function, while low levels might suggest overhydration or other conditions. This test is often used alongside other kidney function tests to diagnose and monitor kidney disease.

Why Might You Need This Test?

Doctors order creatinine tests to evaluate kidney health, especially if you have symptoms like swelling, fatigue, or changes in urine output. It’s also used before surgeries, during pregnancy, or if you have conditions like diabetes or high blood pressure that can affect kidney function.

How Is the Test Done?

A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it’s analyzed to measure creatinine levels. No special preparation is needed, but you may be asked to avoid certain medications or foods that could affect results.

What Are Common Results?

Results are typically reported in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L). While exact ranges vary by lab, higher than expected levels may signal kidney problems, while very low levels could indicate dehydration or other factors.