STDs are a group of diseases transmitted through sexual intercourse. The common ones in China are syphilis, gonorrhea, genital chlamydia trachomatis infection, condyloma acuminata. Genital herpes, AIDS, etc. Mycoplasma genitalium infection, although not classified as a sexually transmitted disease, but also mainly through sexual transmission, the infection is common, but also has a greater risk. Anyone who has sex with a person with an STD may be infected. Therefore, even though a person with an STD has received effective treatment, if he or she has unprotected intercourse with an unexamined and untreated sexual partner, there is a risk of being infected again. The examination and treatment of sexual partners can not only trace other infected people, but also find asymptomatic infected people, which can stop the continued spread of the disease as well as prevent those who have been cured from being infected again. Sexual partners of STD patients within the past 3 months, whether symptomatic or not, should be examined and treated.