STDs are a group of infectious diseases that are transmitted through sexual contact, or similar sexual acts and indirect contact. It can invade the lymph nodes belonging to the genitourinary organs, and even invade various important tissues and organs of the whole body through blood-borne transmission. 1.What are the common sexually transmitted diseases? The classical STDs include: the STDs stipulated in the regulations on the prevention and control of infectious diseases in China include gonorrhea, syphilis, condyloma acuminatum, non-gonococcal urethritis (cervicitis), genital herpes, soft chancre, venereal lymphogranuloma and AIDS. The broad sense of STDs includes more than 20 infectious diseases that can be transmitted through sexual contact, such as genital candidiasis, vaginal trichomoniasis, bacterial vaginosis, pubic lice, scabies, infectious molluscum contagiosum, hepatitis B, amoebiasis and ringworm, which are collectively called the new generation of STDs. 2.How are STDs transmitted? Mainly sexual transmission, followed by mother-to-child transmission, blood-borne transmission and indirect contact transmission. 3.What are the common hazards of STDs? STDs can lead to genitourinary system discomfort, frequent, urgent and painful urination, abnormal discharge; serious can endanger the physical and mental health of patients, can lead to infertility, genital deformity or absence, disfigurement and characteristic sequelae.