Sexually transmitted infections (STIs) are passed during sexual contact.
Some STIs present no symptoms. However, having one can increase the risk of passing on HIV which is why screening is important. Most STIs can be diagnosed quickly and are easily treatable.
The most common STIs include syphilis, chlamydia, gonorrhoea, genital herpes, human papilloma virus (the virus that causes warts), hepatitis B, and hepatitis C. While practising safe sex will protect you from many STIs, some (such as herpes or genital and anal warts) can be passed on despite the use of condoms.