Sexually Transmitted Infections (STIs)
Having sex without a condom puts you at risk of catching a sexually transmitted infection (STI). Many STIs do not have any symptoms, so it is possible to catch them, and pass them on to others, without even knowing. You can get a STI even if you have unprotected sex only once, with one person.
Most STIs can be treated and cured if detected early enough. However, if left undetected and untreated, STIs can affect your health and future fertility.