After the unclean sex man urethra outlet red swelling may be urethritis, circumcision or warts and other reasons. 1. Urethritis: after a man has had unclean sex, the urethra may be attacked by bacteria, inducing urethritis, and after repeated stimulation by inflammation, the urethral outlet may appear red and swollen as well as painful symptoms. 2. glans penis: men have unclean sex, may also lead to bacterial growth in the foreskin area induced glans penis, inflammation can spread to the surrounding tissues, can also cause unclean sex, men’s urethra outlet red and swollen. 3. Acute warts: after men have had unclean sex, they may also be infected by the human papilloma virus, the urethral area is repeatedly stimulated by the virus can also lead to urethral outlet red, swollen, and can be accompanied by genital parts of the symptoms of the growth of superfluous organisms. After the unclean sex man urethral outlet red swelling may also be other causes, such as ureteral stones, urethral stenosis, etc., should go to the hospital in time to clarify the cause of the disease, and choose the appropriate method of treatment.