What Is A Creatinine Test?

Creatinine is a chemical substance in an individual's blood that is a natural waste product of the normal functioning of the muscles in the body. Therefore, those with greater muscle mass naturally have higher levels of creatinine in their blood. Creatinine is filtered from the blood by the kidneys, which makes it a viable way to measure the function of the kidneys. Approximately 0.6 to 1.2 milligrams per deciliter of creatinine can be found in the blood of a male who has normal kidney function, while 0.5 to 1.1 milligrams per deciliter can be found in the blood of a female who has normal kidney function. The discrepancy between the normal ranges for men and women is because men have more muscle tissue on average than women do. An individual's activity level, body size, and the medications they take can also influence their creatinine levels.