Men’s urethral outlet redness may be physiological factors, may also be the manifestation of certain diseases symptoms, such as fungal urethritis, gonorrhea urethritis, trichomonas urethritis, prepuce and glans penis, etc., should be timely consultation to find out the cause of the disease. 1. Physiological factors: men usually do not pay attention to hygiene, the urethra contact with pollutants or not cleaned in a timely manner, there may also be red symptoms, this situation needs to be timely cleaning of the urethra, to keep the urethral opening clean, dry, the symptoms can be gradually relieved. 2. Pathologic factors: (1) fungal urethritis: is caused by fungal inflammatory lesions of the urethra, male urethra will appear local redness and swelling, accompanied by itching symptoms. (2) Gonococcal urethritis: when gonococcal urethritis occurs in men, it will form edema and erosion in the mucous membrane of the urethra, as well as blisters and pustules, and after the rupture of the blisters and pustules, purulent secretion will appear in the opening of the urethra, accompanied by redness and swelling. (3) Trichomonas urethritis: usually trichomonas passes through the urethra after retrograde infection, resulting in inflammation of the urethra, men will have frequent urination, urinary urgency and other symptoms, the urethral orifice is often thin secretion, accompanied by redness and swelling. (4) circumcision and glansitis: when men have long foreskin or prepuce, it will lead to repeated inflammation of the foreskin and glans, and when the inflammation involves the urethra, the urethral opening will also appear red phenomenon. Urethral redness may also be caused by other factors, it is recommended that patients go to the regular hospital as soon as possible for examination, by the doctor to clarify the cause of the disease, give targeted treatment, and strive for early recovery.