Genital herpes in men is caused by infection with the herpes simplex virus. Genital herpes is a sexually transmitted disease caused by the herpes simplex virus. Since the herpes simplex virus can be transmitted through sexual contact, men who have sexual contact with a person with genital herpes, a subclinically infected person, or a person with no manifestation of the virus are at risk of contracting the virus and thus developing genital herpes. High-risk sexual behavior not only leads to an increased risk of genital herpes in men, it also leads to an increased chance of developing various other sexually transmitted diseases. It is therefore important for both men and women to have safe and hygienic sex to prevent the occurrence of sexually transmitted diseases. Men should seek medical attention if they notice any abnormalities such as herpes in their external genital area.