Creatinine

Creatinine is a waste product produced by muscle metabolism and found in the blood and urine. It is an important biomarker used to evaluate kidney function and diagnose kidney damage or disease. Blood creatinine levels are also related to muscle mass, and so are often used to assess physical fitness. High levels of creatinine can indicate a number of conditions such as dehydration, urinary tract infections, acute kidney failure, muscle wasting, or some medicines.