Sexually Transmitted Infections (STIs) are illnesses that are passed on via the exchange of bodily fluids during sexual activity.

Anyone who's sexually active can acquire an STI, particularly people who change partners frequently or do not use a barrier method of protection, such as a condom or dental dam, when having sex.

All STIs can be transmitted via the following routes:

  • Oral sex (both giving and receiving to people of all genders)
  • Penetrative vaginal sex
  • Penetrative anal sex

Some STIs can be transmitted via other routes. See specific infection links for more information.

STIs are not spread by kissing, hugging, swimming in a pool, sitting on toilet seats, or sharing baths, towels, cups, plates, or cutlery.