Serum or Plasma Creatinine Concentration (Mass Concentration)

Why This Test Matters

Creatinine levels can indicate how well your kidneys are working. High levels may suggest kidney damage or disease, while low levels might raise concerns about dehydration or muscle breakdown. Your doctor may order this test to 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

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it’s part of a broader kidney function panel. Drink plenty of water the day before to ensure accurate results, but avoid overhydration just before testing.

During the Test

A healthcare professional will draw blood from a vein in your arm. The process is quick and typically painless. If you’re nervous, let your provider know—they can take steps to make it more comfortable.

What the Results Mean

Results are compared to a reference range, but exact values can vary by lab. High creatinine levels may signal impaired kidney function, while very low levels could indicate conditions like severe dehydration or muscle disorders. Your doctor will discuss your results in the context of your overall health.