The length of male urethra is >18-20cm, and male urethra generally has two bends, mainly the anterior pubic bend and inferior pubic bend, and generally has three strictures, namely the internal urethral orifice, the membrane, and the external urethral orifice. The male urethra is longer, so care must be taken when retaining the urethra to fully insert the urethra into the bladder and insert 1-2cm into the bladder before inflating the balloon when urine is found to avoid urethral injury. Many men have too long urethra and do not effectively insert the urethra into the urethra to inflate the balloon, which can cause the urethra to rupture and bleed.