1, unclean high-risk sex, the first refers to the absence of any protective measures of unsafe sex, this protective measures usually refers to the whole take condom sex, without a condom means that there are more bodily fluids exchange between the two sides; risk size from large to small is the whole without a condom > half wear condom > whole wear condom > just oral sex; 2, multiple sex partners do not wear condoms or condom sex, can also be called sexual promiscuity. Imagine any one of them multiple sex partners, then it will be how confusing the scene, and therefore unintentionally increased the chance of infection; 3, with strange women or men without a condom sex, this kind of sex, including men and women of vaginal sex, men and men of anal sex, especially men and men without a condom anal sex risk is the most; 4, with any “Miss” condom or no condom 4, with any “Miss” condom or condomless sex, especially with Miss sex without a condom has a greater risk, after all, although the domestic Miss industry is very developed, but many are clandestine prostitutes, there is no industry norms or regular medical checkups, so the other party may be sick she is not informed; 5, with any male sexual services called “duck” male condom or condomless Sexual behavior, especially anal sex without a condom, the greatest risk; 6, point 3 said strange women or men, including the Internet or bars or bathing centers and other sexual behavior with strangers, also considered unclean sex high-risk sexual behavior; 7, each time and different sex with the opposite sex before the sex, the opposite sex must be checked for almost all sexually transmitted diseases, to some extent, the most significant reduction in the spread of STDs Although also considered unclean sexual behavior, high-risk does not necessarily count, after all, such a very small number of people; 8, and fixed sexual relations with a fungal infection or HPV infection, and is not considered unclean sex high-risk sexual behavior; 9, oral sex theoretically has the possibility of HIV infection, but the probability is very low, if the sexual behavior, only oral sex without any direct contact with the sexual organs, and is not really 10.Mere masturbation or body fluids touching the sexual organs is not considered high-risk sexual behavior; 11.The use of drugs in public syringes or blood products of unknown origin is also a high-risk way to transmit HIV and syphilis, but it is not high-risk sexual behavior; 12.Other high-risk sexual behaviors that people consider as unclean sex.