Transmission of HIV is relatively more difficult from women to men and easier from men to women, but not nearly impossible. In reality, many men living with HIV are infected through heterosexual sex. However, in recent years, with the increase in homosexual behavior, it is becoming more common for men with HIV to have sex with men. HIV is mainly transmitted sexually, through unprotected sex. Therefore, to avoid AIDS, it is essential to avoid having sex before marriage, to avoid sexual promiscuity, to wear condoms, and not to have unclean sex. After exposure has occurred, anti-HIV medication needs to be taken promptly.