Lemon is rich in citric acid, which can inhibit the formation of stones in the body. Therefore, regular consumption of lemon or lemon water can prevent stone formation by increasing the content of citric acid, which inhibits stones and the formation of related crystalline components or stone precursors. After drinking lemon water it also increases the body fluid content and dilutes the urine so that the urine does not contain more of the components that lead to the formation of stones and crystalline precursors. For patients who already have urinary stones, drinking more lemon water can increase the volume of urine and promote the discharge of stones, as well as prevent further increase in stone size, but need to be combined with extracorporeal shock wave lithotripsy or with other medications to assist in the treatment, or as a kind of surgery, drinking more water and urinating more after surgery to promote the discharge of stones as an adjunctive treatment. For patients who do not suffer from urinary stones, regular consumption of lemon water or lemon can increase the content of citric acid in the body and reduce the probability of stone occurrence.