Safe Sex 安全的性行为 Topic Overview 关于安全性行为的综述 Sexually transmitted diseases（STDs）are spread by sexual contact involving the genitals, mouth, or rectum, and can also be spread from a pregnant wom
Sexually transmitted diseases（STDs）are spread by sexual contact involving the genitals, mouth, or rectum, and can also be spread from a pregnant woman to her fetus before or during delivery. STDs, which affect both men and women, are a worldwide public health concern.
While most STDs can be cured, some cannot, including HIV（which causes AIDS）, genital herpes, and human papillomavirus（HPV）, which can cause genital warts.
STDs can be spread by people who don't know they are infected. Always use protection every time you have sex, until you are sure you and your partner are not infected with an STD.
If you are in a relationship, delay having sex until you are physically and emotionally prepared, have agreed to only have sex with each other, and have both been tested for STDs.
Abstinence as prevention
Completely avoiding sexual contact（abstinence）, including intercourse or oral sex, is the only certain way to prevent an infection.
Discuss safe sex with your partner
Discuss STDs before you have sex with someone. Even though a sexual partner doesn't have symptoms of an STD, he or she may still be infected.
Questions to ask someone before having sex include：
How many people have you had sex with？
Have you had sex without a condom？
Have you ever had anal sex？
Have you ever had unprotected oral sex？
Do you have many sex partners？
Do you inject illegal drugs or have you had sex with someone who injects drugs？
Have you ever had unprotected sex with a prostitute？
Have you ever had an STD, including hepatitis B or hepatitis C？Was it treated and cured？
Safe sex practices
Some STDs, such as HIV, can take up to 6 months before they can be detected in the blood. Genital herpes and the human papillomavirus（HPV）can be spread when symptoms are not present. Even if you and your partner have been tested, use condoms for all sex until you and your partner haven't had sex with another person for 6 months. Then get tested again.
Watch for symptoms of STDs, such as unusual discharge, sores, redness, or growths in your and your partner's genital area, or pain while urinating.
Don't have more than one sex partner at a time. The safest sex is with one partner who has sex only with you. Every time you add a new sex partner, you are being exposed to all of the diseases that all of their partners may have. Your risk for an STD increases if you have several sex partners at the same time.
Use a condom every time you have sex. Latex and polyurethane condoms do not let STD viruses pass through, so they offer good protection from STDs. Condoms made from sheep intestines do not protect against STDs.
Use a water-based lubricant such as K-Y Jelly or Astroglide to help prevent tearing of the skin if there is a lack of lubrication during sexual intercourse. Small tears in the vagina during vaginal sex or in the rectum during anal sex allow STDs to get into your blood.
Avoid douching if you are a woman, because it can change the normal balance of organisms in the vagina and increases the risk of getting an STD.
Be responsible. Avoid sexual contact if you have symptoms of an infection or if you are being treated for a STD or HIV. If you or your partner has herpes, avoid sexual contact when a blister is present and use condoms at all other times.