Serum or Plasma Creatinine Concentration (Mass Concentration)

Why This Test Matters

Creatinine levels can indicate how well your kidneys are working. High levels may suggest kidney damage or disease, while low levels could be due to muscle mass changes or other conditions. This test is often used alongside other measures to monitor kidney health, especially in people with diabetes, high blood pressure, or a history of kidney problems.

What to Expect Before the Test

No special preparation is needed unless your doctor specifies. You may be asked to fast for a few hours before the test if it involves a blood draw, but this is rare for creatinine alone. Drink plenty of water the day before if you’re having blood drawn, as it helps ensure accurate results.

What the Results Mean

Results are typically reported in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L). While reference ranges vary by lab, higher than expected levels may signal kidney issues, while very low levels might need further investigation. Your doctor will interpret results in the context of your overall health.

Common Causes of Abnormal Results

High creatinine levels can result from kidney disease, dehydration, severe muscle damage, or conditions like heart failure. Low levels may occur with low muscle mass, liver disease, or certain medications. Other factors, like recent exercise or certain medications, can temporarily affect results.