Serum or Plasma Creatinine Concentration (Standard Method)

Why This Test Matters

Creatinine is a byproduct of muscle breakdown and is normally filtered out of your blood by your kidneys. If your kidneys aren’t working well, creatinine levels can build up in your blood. This test helps doctors monitor kidney health, especially if you have conditions like diabetes, high blood pressure, or a history of kidney problems.

What to Expect Before the Test

You may be asked to fast for a few hours before the test, but this isn’t always required. The test is usually done by drawing blood from a vein in your arm. If you’re on dialysis or have a kidney-related condition, your doctor may recommend this test more often to track changes in kidney function.

What the Results Mean

Results are compared to a general reference range, but your actual range may vary based on age, sex, muscle mass, and overall health. High levels may signal kidney problems, while very low levels could indicate muscle wasting or other conditions.

Common Causes of Abnormal Results

High creatinine levels can be caused by kidney disease, dehydration, severe muscle damage, or conditions that reduce blood flow to the kidneys. Low levels might be due to muscle disorders, liver disease, or certain medications.