Serum or Plasma Creatinine 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 levels can rise. This test helps doctors monitor kidney health, especially in people with conditions like diabetes, high blood pressure, or those taking certain medications that affect kidney function.

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 sometimes a urine sample may be collected (depending on the specific test ordered). Drink plenty of water the day before if your doctor suggests it, as it can help dilute creatinine levels in urine.

What the Results Mean

Results are typically compared to a reference range that varies by lab and age. Higher levels may indicate kidney problems, while lower levels might suggest muscle mass issues or liver disease. Your doctor will interpret results in the context of your overall health.

Common Causes of Abnormal Results

Elevated creatinine levels can be caused by kidney disease, dehydration, severe muscle damage, or certain medications. Low levels may occur with muscle wasting, liver disease, or overhydration. Always discuss any concerns with your healthcare provider.