Plasma or Serum Creatinine Concentration (Mass)

Why This Test Matters

Creatinine is a byproduct of muscle breakdown and is filtered out of your blood by your kidneys. High levels can indicate reduced kidney function, while low levels might suggest dehydration or other conditions. This test is often used alongside other measures to evaluate kidney health, especially if you have symptoms like fatigue, swelling, or changes in urine output.

What to Expect During the Test

You’ll typically have a small blood sample drawn from a vein in your arm. If you’re tested for urine creatinine, a sample may be collected over a 24-hour period. The test is usually done in a lab and results are ready within a few days.

Factors That Can Affect Results

Several factors can influence creatinine levels, including muscle mass (higher muscle mass can lead to higher levels), dehydration or fluid overload, certain medications, and kidney-related conditions. Recent exercise or muscle damage can temporarily raise levels.

Common Causes of Abnormal Results

High creatinine levels may signal kidney disease, dehydration, or conditions like heart failure or muscle disorders. Low levels might suggest dehydration, overhydration, or conditions affecting muscle metabolism.