Kidney stones with a size of 3mm are very small, if they are found without medication or extracorporeal shock wave lithotripsy, most of them can be discharged from the body with urine and will not cause any conscious symptoms. In a very small number of patients, the stones may adhere to the kidneys for a long time and cannot be discharged by themselves. Only regular ultrasound review and regular observation is needed. 3mm or so kidney stones will not cause back pain, hematuria, frequent urination, urinary urgency and other symptoms, and the vast majority of patients may be able to eliminate the stone by themselves within a week or so after drinking more water. It is recommended to drink more than 2000mL of water per day, and in the process of urination, collect the relevant urine to observe whether the stones are eliminated from the body on their own. In addition to drinking more water in daily life, it is also necessary to reduce the intake of oxalic acid or purine substances, such as drinking strong tea for a long time, chocolate, eating seafood, animal offal and barbecue, etc., which will increase the probability of suffering from kidney stones.