A Creatinine test measures the level of creatinine in your blood, which is a waste product formed from normal muscle activity. Your kidneys filter creatinine out of the blood, so elevated levels usually indicate that the kidneys are not working properly. Doctors commonly recommend this test to evaluate kidney function, diagnose kidney disease, or monitor existing kidney conditions. Symptoms such as swelling, fatigue, changes in urination, or high blood pressure may also prompt this test.

For the Creatinine test, a small blood sample is collected from a vein, and fasting is generally not required unless advised by your doctor. The test is often performed along with Blood Urea Nitrogen (BUN) and eGFR calculations to get a complete picture of kidney health. It helps detect early kidney problems and monitor how well treatments are working.