Difficulty in urinating after the removal of spinal nails may be due to nerve damage, irritation of the ureter, and lesions of the urinary system itself. 1. Nerve damage: mainly from two aspects: the first may be the operation of pulling stimulation or direct accidental injury to the spinal cord nerves, because the primary nerve center of the bowel function is located in the spinal cord cone and sacral nerves; the second may be anesthesia related to the operation, if the anesthesia is taken to the lumbar joint anesthesia or lumbar anesthesia, it may result in the inhibition of the central urinary tract, there will also be difficult to pass urine after the operation. 2. Ureteral stimulation, urinary system diseases: preoperative is if under the urinary catheter patients, postoperative urinary difficulties may also occur, because the urinary catheter stimulation will cause urethral mucosal damage, resulting in a transient bladder contraction dysfunction, most of which can be restored to normal; middle-aged and elderly patients, if they themselves have prostate hyperplasia, prostatitis, etc., surgical stimulation may also lead to urinary difficulties occur. There may be other reasons why it is difficult to urinate after the removal of spinal nails, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment under the guidance of the doctor.