We get a lot of questions about the difference between STI and STD, and the answer is actually pretty simple: there isn’t really a difference.
STD stands for “sexually transmitted disease,” and STI stands for “sexually transmitted infection.” But no matter which term people use, they're talking about the same thing: infections that get passed from one person to another during sex.
These infections have had many different names over the years: venereal disease (VD), “the clap,” “the drip,” and most recently, STD and STI. STI is the most up-to-date term — educators and health care providers switched from STD to STI because “infection” is more accurate and less stigmatizing than “disease.” Let’s break it down:
An infection happens when a virus, bacteria, or parasite enters your body, and your immune system kicks in to try to fight it. Disease happens when the infection causes symptoms, damages parts of your body, and leads to illness. Many infections never develop into diseases.
Most of the time, STIs never get to the disease stage — people may not even know when they have one. STIs usually don’t cause symptoms, and they can often be treated or cured with medicine before they cause long-term harm. And it’s an infection, not a disease, that gets passed between people during sexual contact. So using “infection” just makes more sense.
The word “disease” also sounds loaded and scary, which can actually be harmful. There’s already a lot of unnecessary stigma around STIs just because you can get them from sex (and unfortunately, our culture has a lot of negative attitudes about sex). Calling STIs “diseases” only adds to the stigma and misinformation — and this makes it even harder for people to talk honestly with their partners, get tested, and have safer sex (which are all the best ways to prevent STIs). The more we can fight the stigma and confusion around STIs, the healthier everyone will be.
But here’s the catch: “STD” has been around longer, and way more people use that term. Most patients say “STD” in health centers, and more people search for “STD” than “STI” on the Internet. So some health educators, providers, and organizations still choose to use STD because it’s the term most people know.
For example, we often use “STD” on plannedparenthood.org, so more people can easily find the information they need when they search online. While the sex educators of the world try to change old habits and switch everyone over to STI, we gotta meet people where they’re at in the meantime.
At the end of the day, it doesn’t really matter if you call ‘em STDs, STIs, down-there boo boos, the genital sads, or whatever else you can think of. What matters is that we’re protecting ourselves and each other by having safer sex, getting tested, and fighting STI stigma.