what is a creatinine level
Creatinine is a waste product produced by muscles from the breakdown of a compound called creatine. Almost all creatinine is filtered from the blood by the kidneys and released into the urine, so blood levels are usually a good indicator of how well the kidneys are working. The kidneys are a pair of bean-shaped organs that are located at the bottom of the ribcage in the right and left sides of the back.