The words "STI or STD" against a blue and light tan background

Why do some people say “STIs” instead of “STDs”? Is there a difference?

Great question! STI stands for sexually transmitted infection, while STD stands for sexually transmitted disease. STI and STD are usually used to mean the same thing: an infection that’s spread through sexual contact, including penis in vagina (PIV) sex, anal sex, oral sex (going down on, blow job, eating out) and sometimes direct genital-to-genital contact.

Technically, though, there is a difference between the two.

An infection turns into a disease when symptoms appear. For example, when left untreated, the infection chlamydia can turn into the disease pelvic inflammatory disease. However, many people with STIs don’t have symptoms for years, or have symptoms so mild they don’t even notice them. This is why the only way to know for sure whether you have an STI/STD is to get tested. More people are beginning to use the term “STI” because it’s more accurate.

Plus, there’s a lot of stigma attached to the term STD. Some people hope that emphasizing “infection” instead of “disease” can help ease the embarrassment that some feel about having or talking about STIs/STDs.

Whether you say STIs or STDs, it’s important to understand how they’re spread, and how you can take care of your sexual health.

If you’re having sex, get regularly tested, use condoms and/or dental dams, and talk about safer sex with your partner. If you have a vagina and are having or thinking about having PIV sex, talk to your health care provider about your birth control options. Make sure you you and your partner understand consent.

10-22 years old in NYC? Call (212) 423-3000 to make an appointment for confidential STI testing and treatment, birth control and other health care at the Mount Sinai Adolescent Health Center—all at no cost to you.