Kidney stones have been causing back pain or abdominal pain because of the following reasons: 1. Kidney stones cause hydronephrosis, kidney stones can cause obstruction of the renal pelvis outlet, and the urine produced by the kidneys is blocked from being removed and will accumulate within the kidneys to produce hydronephrosis. When the pressure rises, the kidney’s peritoneum will feel the pressure and experience tension pain, which may be accompanied by nausea and vomiting. Therefore, if the kidney stones are not discharged from the body and the hydronephrosis is not relieved, there will be pain all the time. 2. Stones combined with local mucosal rupture, bleeding or infection can produce a local inflammatory reaction and cause persistent pain. In addition to pain, it can also be accompanied by frequent urination, urgent urination or bleeding in urination; 3. Kidney stones can produce different degrees of pain after discharging into the ureter, because the lumen of the ureter is relatively thin, and after entering the ureter, it can be accompanied by different degrees of obstruction and lead to hydronephrosis, and even after discharging into the ureter, the pain can be aggravated.