Suggestion: avoid drinking too little water. The human body excretes a lot of metabolites from urine every day, and at the same time, it should concentrate urine as much as possible to reduce the loss of body fluids. According to statistics, if the daily urine volume of human body is below 1000 ml, the probability of crystal formation will increase obviously, and if it is less than 500 ml, there is a danger of stone formation.