Serum/Plasma Creatinine Concentration (Standard Method)

Why This Test Matters

Creatinine is a byproduct of muscle metabolism that your kidneys filter out of your blood. High levels can indicate poor kidney function, while low levels may suggest dehydration or other conditions. 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 usually needed, but you may be asked to fast for 8–12 hours before the test if it’s part of a broader panel. Drink plenty of water the day before to ensure your kidneys are functioning normally. Avoid strenuous exercise or medications that might affect kidney function (like certain pain relievers) unless instructed otherwise.

How the Test Is Performed

A blood sample is drawn from a vein in your arm by a healthcare professional. The sample is sent to a lab, where creatinine levels are measured using a standardized method that detects the substance’s concentration in your blood or plasma.

What the Results Mean

Results are typically reported as a numerical value (e.g., milligrams per deciliter or micromoles per liter), but your doctor will interpret them in relation to your overall health, age, sex, and other factors. High levels may signal kidney issues, while very low levels could raise concerns about hydration or muscle metabolism.