Serum Creatinine (Creatinine Level)

Why This Test Matters

Creatinine is a byproduct of muscle breakdown and is naturally filtered out by your kidneys. High levels may indicate reduced kidney function, while low levels could suggest muscle underuse or overhydration. This test is often used alongside other measures to monitor kidney health, especially in people with risk factors like diabetes, high blood pressure, or a family history of kidney disease.

What to Expect Before the Test

No special preparation is needed for this test. You may have a small needle inserted into a vein in your arm to draw blood. If you’re on a low-protein diet or have recently exercised, your doctor may advise timing your test to avoid potential fluctuations in creatinine levels.

Common Causes of Abnormal Results

High creatinine levels may signal impaired kidney function, dehydration, or conditions like heart failure or severe muscle damage. Low levels might suggest dehydration, overhydration, or conditions affecting muscle mass (e.g., malnutrition). Always discuss your results with your healthcare provider, as they’ll consider your full medical history and other test results.

When You Might Need This Test

Your doctor may order this test to evaluate kidney function before surgeries, check for kidney disease, monitor chronic conditions like diabetes or heart disease, or assess symptoms like fatigue, swelling, or changes in urine output.