What Are the Chances of Having an STD?

If people are sexually active and not using condoms, what is the possibility of them having a disease?
– Kamyra*

Unfortunately, it's quite likely. People who have sex without using condoms are at high risk of getting sexually transmitted diseases (STDs).

It doesn't matter how many people the person has had sex with. Even if someone has only had one sexual partner, that partner could have a disease. Of course, the chances of getting STDs (also called sexually transmitted infections, or STIs) are even higher if a person has unprotected sex with lots of different partners.

Many people who have STDs do not have obvious signs or symptoms. Because of this, they may believe they're "clean" and tell partners there's no need to use a condom. But that's not safe. For example, about 6 out of 10 young people with HIV don't know they're infected. So they risk passing the virus, which causes AIDS, on to others.

Even getting treatment isn't a completely foolproof way to stop STDs from spreading. Some STDs (like trichomoniasis) can be treated so they go away, but other infections (like herpes or HPV) will always be in a person's body, even if that person has been treated.  Plus, if someone has been treated for an STD like chlamydia and it goes away, that same person can still get re-infected if exposed to the STD another time.

Anyone who is planning to have sex, or who has had sex, should be tested for STDs. And always use condoms for protection — every time.

*Names have been changed to protect user privacy.