Serum or Plasma Free Creatinine Concentration (Mass Concentration)

Why This Test Matters

Creatinine is a byproduct of muscle breakdown and is normally filtered out by your kidneys. High levels may indicate reduced kidney function, while low levels could suggest dehydration or overhydration. This test helps doctors monitor kidney health, especially in people with diabetes, high blood pressure, or other conditions that affect the kidneys.

What to Expect Before the Test

No special preparation is needed for this test. You may have a blood draw, where a small needle is used to collect a sample from your arm. If you’re on dialysis or have kidney disease, your doctor may advise timing your test around your treatment schedule to get the most accurate results.

What the Results Mean

Results are typically compared to your baseline or reference ranges provided by your lab. Elevated levels may signal kidney problems, while persistently low levels could warrant further investigation into hydration status or muscle mass.

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 dehydration, overhydration, or certain medications that affect kidney function.