A single insertion of a urinary catheter may also cause urethral dilatation. A common clinical urethral intubation is catheterization, which may cause some degree of urethral dilatation if done incorrectly or if the urethra is left in place for a long period of time. Under normal circumstances, catheterization should be fully lubricated first, and gentle and slow operation, the correct insertion of urinary catheter operation, a short period of indwelling urinary catheter generally does not cause significant urethral dilatation, after removal of the urinary catheter urethra will soon return to normal. When urinary catheterization is performed incorrectly, the balloon is inflated and fixed before the tip of the urethra is fully inserted into the bladder, which usually results in urethral dilatation, or bleeding from urethral mucosal tears. After the removal of a prolonged indwelling urinary catheter, the urine line will become thicker, indicating a certain degree of urethral dilatation, which is also a common phenomenon, and can be returned to normal within a few days. Clinical indwelling urinary catheter need to pay attention to observe whether there is frequent urinary urgency urinary pain, abdominal pain, testicular pain and other symptoms, to prevent urinary tract infections, discomfort promptly notify the physician to deal with.