The only 100 percent effective way to avoid getting a sexually transmitted disease (STD) is to abstain from sexual touching below the waist, such as rubbing bodies without clothes, vaginal-penile sex, oral sex and anal sex. Your next best bet is to practice safer sex, such as using a condom and/or dental dam every time and getting tested regularly for STDs and asking your partners to do the same.

STDs cannot spontaneously occur. There is risk only when one person already has an STD in their body. The trick is that it’s very difficult to know if you or your partner is already infected, so it is better to be safe. You can’t always rely on what you see to tell you whether or not an infection is present since most STD infections do not have any symptoms. For example, you could have the herpes virus in your body and never have an outbreak of sores.

While different STDs are spread in different ways, most are spread through skin-to-skin genital contact or getting sexual fluids (and sometimes blood) in the mouth, urethra of the penis, anus or vagina.

This means that touching above the waist with clothes on is safe. But just about every other kind of close sexual contact with an infected partner carries some risk (sometimes very low, sometimes very high) of getting an STD.

So, if you decide to be sexual with a partner, here are some things you can do to reduce your chances of getting an STD.

• Practice safer sex with each partner each time. Fenway Community Health has a great brochure that can teach you how to be a safer sex expert!
• Get tested regularly, and always get tested BEFORE you have sex with a new partner. Your partner should also be tested.
• Know your partner well before having sex. Ask your partner if they've ever had an STD and if it was treated. Ask them when they last got tested and if they are willing to get tested again. Ask them if they practiced safer sex with past partners and if that included oral sex. Know that people sometimes don’t know they have an infection or may not consider certain behaviors risky, when in fact they are.
• Learn about STDs, how they are transmitted, and which activities are low-risk and which are high-risk so that you can make informed decisions about how to protect your sexual health. For example, kissing and massage are low-risk. Unprotected vaginal or anal sex are high-risk.
• Choose your sexual partners carefully. Take relationships slowly so you have the chance to get to know someone, what they’re about, what their sexual history is like, and how they treat you in general. The more time you spend with someone, the greater the likelihood you will develop a relationship that is healthy and includes open, honest communication about these important issues. Also remember that the more sexual partners you have, the greater your chances of getting an STD.
• Even if you've both been tested and nothing has shown up, you should still use latex barriers like condoms every single time you have sex to guarantee that you both remain safe and protected.

You should also use condoms if you have oral sex. Flavored condoms are made specifically for oral sex and are available in most drugstores. Females should use a dental dam, such as a Sheer Glyde Dam, to cover their vulva. A condom cut open and placed over the woman's genitals is also an effective barrier, and some people use Saran Wrap (non-microwavable) for oral sex on a woman, which is better than not using any protection. Still, a Sheer Glyde Dental Dam offers the best protection during oral sex on a female.

For more information on STDs, click here or check out these Sex, Etc. stories from other teens.

Got a question about STDs? Call the American Social Health Association’s national STI hotline at 1-919-361-8488, the hotline is open 8 a.m. – 8 p.m. E.S.T.