Serum or Plasma Creatinine Concentration (Standard Method)

Why This Test Matters

Your kidneys normally filter waste products, including creatinine, from your blood. High levels may signal kidney problems, while low levels could indicate dehydration or muscle breakdown. 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 During the Test

A blood sample is taken from a vein in your arm. You may feel a slight pinch, but it usually takes only a few minutes. No special preparation is needed unless your doctor specifies otherwise.

How the Results Are Used

Doctors use creatinine levels to calculate a measure called the **glomerular filtration rate (GFR)**, which estimates how well your kidneys filter blood. Low GFR may indicate kidney damage or disease, while consistently high levels could prompt further evaluation.

Common Causes of Abnormal Results

Creatinine levels can rise due to kidney disease, dehydration, severe muscle injury, or conditions that reduce blood flow to the kidneys. They may also drop if you’re overhydrated or have muscle wasting (e.g., from illness or malnutrition).