If you want to avoid contracting AIDS, you should know how it is transmitted so that you can prevent it. AIDS can be transmitted through sexual transmission, blood transmission and mother-to-child transmission. If you want to prevent sexual transmission, you should keep regular sexual partners and try to use condoms for sex, which is one of the most effective measures to prevent AIDS and sexually transmitted diseases (STDs). For blood transmission, one should avoid sharing syringes with others to avoid exchange of blood, and avoid invasive operations in irregular medical institutions, such as tooth extraction, ear piercing, eyebrow tattooing and so on. For mother-to-child transmission, mothers with HIV should go to a specialized hospital as soon as possible during pregnancy to avoid infecting their babies with the virus through mother-to-child interruption.