Kidney stones fall down, can enter the bladder, can also enter the ureter, can also enter the urethra, are a kind of stone discharge phenomenon, the urinary system belongs to the semi-closed system, the opening is located in the body of the urethral orifice, the other system belongs to the closed system. For example, the kidney connects the ureter, connects the bladder connects the urethra, so the path of stone discharge is the first to fall into the ureter, and then through the ureter into the bladder after the ureter, and then by the urine scouring or carrying the urethra from the mouth of the discharge, that is, to complete a complete stone discharge process. In the process of the stone falling out, it may stay in the ureter or bladder, urethra, which can cause different symptoms. For example, if the stone stays in the ureter, it can cause obvious back pain or abdominal pain, accompanied by nausea, vomiting, or frequent urination, urgency and other symptoms. After the kidney stone is expelled from the ureter and enters the bladder, the pain, urinary frequency, urinary urgency and vomiting symptoms can be immediately reduced or disappear. However, until they are removed from the body, they can cause discomfort in the lower abdomen or cause bleeding in the urine. If the bladder stone enters the urethra, it can cause a feeling of urinary obstruction with difficulty in urination, but these symptoms can be completely eliminated after the stone is expelled from the body.