Creatinine

Creatinine is a waste product made by your muscles and removed from the blood by the kidneys. Measuring it gives a reliable indication of how well your kidneys are filtering the blood.

A raised creatinine level may indicate that the kidneys are not working as efficiently as they should, while the value is often used to estimate overall kidney function. Because diet, muscle mass and hydration can influence it, the result is interpreted alongside other kidney tests.