Kidney stones are not painful but can appear as blood in the urine. This is a common condition, and is often seen when excessive activity or exercise causes the stones to rub against the mucous membrane and cause it to break down, so that blood is mixed with the urine and appears as blood in the urine. However, if the stone is not obstructed, it will not produce pelvic hypertension or hydronephrosis, so there will be no pain. If the stone is not discharged into the ureter and does not cause spasm of the ureter, there will be no painful symptoms. After drinking more water and urinating more often, the bleeding can gradually become lighter or disappear when the urine is diluted. It is also important to reduce strenuous exercise, because strenuous exercise can lead to increased friction between the stone and the mucous membrane, which can cause the bleeding to worsen. For patients with large amount of bleeding and generalized hematuria, it is necessary to go to the hospital for further examination to determine whether there is a combination of infection or other causes in the body that lead to the aggravation of bleeding, such as the presence of thrombocytopenia or coagulation dysfunction in the patient, and the mucosa will not clot easily after the mucosal rupture, which will lead to persistent bleeding.