Urethral discharge is caused by urethritis, the causes of urethral discharge are: First, microbial invasion of the urethra and caused by microorganisms, such as gonococcus, mycoplasma, chlamydia, Candida albicans, bacteria that reside in the human body for a long time. Second, urethral injury, urethral instrumentation caused by the urethral mucosa abrasions, can also lead to bacterial infection. Third, unclean sexual life. Fourth, urethral obstruction, including narrow foreskin mouth, narrow external urethral opening, so that urination is not smooth, the accumulation of fluid left in the urethra, so that the urethra infection, causing pus and other phenomena, found that this situation should be treated in a regular male hospital.