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 properly, creatinine levels can build up in your blood. This test is a key part of evaluating kidney health and diagnosing conditions like chronic kidney disease.

What to Expect Before the Test

No special preparation is needed for this test. You may have a blood sample drawn from a vein in your arm, or if testing urine, you’ll collect a sample in a container at home or a clinic. If you’re on a low-protein diet or have recently exercised, let your healthcare provider know, as these may temporarily affect results.

What the Results Mean

Results are typically reported in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L). Higher than expected levels may indicate kidney problems, while lower levels could suggest muscle loss or other conditions. Your doctor will interpret results in relation to your overall health and medical history.

Common Causes of Abnormal Results

Elevated creatinine levels may be due to kidney disease, dehydration, severe muscle damage, or conditions that reduce blood flow to the kidneys. Lower levels might be linked to malnutrition, liver disease, or certain medications. Always discuss any concerns with your healthcare provider.