Creatinine can be divided into blood creatinine and urine creatinine, if there is a decrease in blood creatinine, it often indicates that the kidney function is gradually recovering, that is, the glomerular function is recovering. However, if the decrease in blood creatinine is caused by the patient eating less for a long time, it does not mean that the condition is improving, because blood creatinine is a product of muscle metabolism and decomposition, and blood creatinine will decrease if the patient eats too little. If there is a decrease in urine creatinine, it often indicates that the kidney function has not been restored, or even further deteriorated. Because urine creatinine is filtered by the glomerulus, if the glomerulus function is poor filtration rate decreases, urine creatinine will appear to decline.