Kidney function mainly refers to the filtration function of the kidney, that is, the ability to detoxify. The filtration function of the kidney is usually represented by the glomerular filtration rate, which is normally between 80-120 ml/min/1.73 m2. In addition, blood creatinine is commonly used clinically to replace as well as estimate glomerular filtration rate. For blood creatinine the normal range is usually between 44-133 μmoI/L, with gender differences, with the normal range for women being approximately between 44-84 μmol/L and for men between 62-106 μmol/L. Because men have a higher metabolic rate than women, men produce more blood creatinine metabolically than women. Of course, the reference values vary slightly depending on the tests performed by different laboratories. Another indicator of kidney function is urea nitrogen, whose normal range is between approximately 2.1-8.2 mmol/L.