STDs A to Z

Sexually transmitted diseases, or STDs—also called sexually transmitted infections, or STIs—affect people of all ages, backgrounds, and from all walks of life. In the U.S. alone there are about 20 million new cases each year, about half of which are in young people ages 15-24 years.

Getting the facts about STIs and sexual health is increasingly important. We invite you to explore our website and learn more about specific STIs, tips for reducing risk, and ways to talk with healthcare providers and partners.


While you’ll see both terms used, there has been a shift in recent years to STI. Why? The concept of “disease,” as in STD, suggests a clear medical problem, usually some obvious signs or symptoms. But many common STDs have no signs or symptoms in most of the people who have them. Or they have mild signs and symptoms that can be easily overlooked. So the sexually transmitted virus or bacteria can be described as creating “infection,” which may or may not result in “disease.” This is true of chlamydia, gonorrhea, herpes, and human papillomavirus (HPV), to name a few.

But there is not consensus in the medical and public health community, as H. Hunter Handsfield, MD, Professor Emeritus at Washington University Center for AIDS and STD notes in his essay for the journal Sexually Transmitted Diseases. While making arguments for both terms, Handsfield suggests, “Those who prefer either term should use it freely, with neither defensiveness nor pride in either one.” Read his thoughts and share your comments on STD Prevention Online.

Or is it time for a new term? Medical linguist Janet Byron Anderson, PhD, argues that we do and proposes “sexually transmissible infectious disease (STID).” You can read her take here.

Your Safer Sex Toolbox

Learn about how to make sex safer for you and your partners and prevent STIs.

Getting Tested for STIs

Getting tested can be quick and easy—find a place to get tested near you.

Oral Sex and STIs

Can you get an STI from oral sex? In short, yes. Learn more about reducing your risk.

Talking about Sex

No matter how long you and your partner have been together, you will need to keep communicating about your sexual expectations, desires and needs.

Have a question about STI testing? Ask an expert!