Serum or Plasma Creatinine Concentration (Substance Concentration)

Why This Test Matters

Creatinine levels can indicate how efficiently your kidneys filter blood. High levels may signal kidney problems, while low levels could suggest dehydration or muscle loss. 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 disease.

What to Expect Before the Test

No special preparation is needed for this test. You may have a blood draw (serum/plasma) or a urine sample (if part of a 24-hour collection). If you’re taking certain medications, let your provider know, as they may affect results.

Common Causes of Abnormal Results

Elevated creatinine levels may be due to kidney disease, dehydration, or conditions that reduce blood flow to the kidneys. Low levels might result from dehydration, muscle atrophy, or overhydration. Other factors, like recent exercise or certain medications, can also influence results.

When You Might Need This Test

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