What's an STD?

Dear Alice,

Sorry to ask and sound stupid, but, what are STDs?


Dear STD,

No need to apologize. Your question reflects your interest in learning, and there's nothing wrong with wanting to stay informed. Lots of people don't know what an STD is! STD is an abbreviation for sexually transmitted disease, and is a term that has replaced VD or venereal disease. Today, the more commonly used term is STI, which stands for sexually transmitted infection. A sexually transmitted infection is an infection that is passed on through sexual activity from a person who already has an STI.

The explanation for the shift in terms from STD to STI is simple, yet significant. The term infection means that a germ is present in a person's body, but the person may not have any signs or symptoms of the infection. The term disease means that the infection is causing obvious signs or symptoms in the person. Thus, a sexually transmitted germ — bacteria, virus, parasite, or fungi — causes an infection, which may or may not result in a disease. This distinction is critical because many sexually transmitted infections don't result in signs or symptoms, so a person may have an STI and not know it. Essentially, the term STI is a more encompassing term than STD. Some organizations or websites continue to use the term STD or use the terms STD and STI interchangeably.

When it comes to STIs, who all is at risk of contracting one? Every sexually active person is at risk for contracting an STI if a partner is infected. To help reduce your risk, you may want to follow safer sex guidelines. If you think you may have an STI, you could consider seeing your health care provider for a checkup. It's a good idea to regularly get checked for STIs if you're sexually active, even if you don't experience symptoms. 

Safer sex means reducing skin-to-skin contact and contact with bodily fluids, including semen, vaginal floods, and blood, between partners. Safer sex includes ways of minimizing the risk of spreading HIV and other STIs. Some of these guidelines include:

  • Using a condom correctly and consistently every time a person has vaginal, anal, or oral sex (and using a new condom if switching from one form of sex to another or switching partners)
  • Using a latex barrier for cunnilingus (oral-vulva contact ) and anilingus (oral-anal contact) – such as a dental dam, a non-lubed condom (that has its ring removed, cut down the length, and opened up to form a rectangle), or non-microwaveable plastic wrap
  • Mutual masturbation (masturbating together)

Sex without taking additional precautions can put an individual at risk for HIV and other STIs. This allows semen, vaginal lubrication, or blood (body fluids) to be passed from one person to another. These body fluids may then spread viruses or bacteria to the other partner. You may find the Sexually Transmitted Infections (STIs) category of the Go Ask Alice! Sexual & Reproductive Health archives to be helpful for learning more.

Last updated May 15, 2020
Originally published Dec 06, 1996

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