Kidney stones of 3mm in size are meaningless kidney stones, most of which can be excreted by themselves through urination and usually do not cause obvious conscious symptoms and are found during physical examination. Patients only need to drink more water and urinate more often, and do not need to take medication or undergo extracorporeal shock wave lithotripsy treatment. Patients should drink more than 2,500mL of water per day, and it is recommended to visit the hospital at intervals of about 2-3 weeks to check the status of stone removal. In a very small number of patients, there may be transient pain in the lower back and abdomen during stone removal, or transient pain in urination, suggesting that the stone has been discharged into the ureter or out of the body. In addition to drinking more water in daily life, you should also pay attention to reduce the intake of oxalic acid, such as spinach, bamboo shoots, strong tea, chocolate, cocoa and other foods are rich in oxalic acid, you need to reduce the intake of these foods. Also need to reduce the intake of high purine food, commonly used foods include a variety of seafood products, barbecue products, animal offal, etc., long-term consumption may occur in the kidney stones.