Syphilis is a bacterial infection usually passed on through sexual contact including unprotected vaginal, anal or oral sex as well as close genital contact.
Symptoms begin with a painless but highly infectious sore on your genitals, or sometimes around your mouth. If somebody else comes into close contact with the sore, usually during sexual contact, they can become infected. The sores last two to six weeks before disappearing.
Secondary symptoms, such as a skin rash and sore throat, then develop. These may disappear within a few weeks, and you might not experience any other symptoms for years. After this, syphilis can progress to its third, most dangerous stage, known as tertiary syphilis which affects the bones, skin, nervous tissue, heart, and arteries.
Caught early syphilis can be treated with antibiotics. If it is left untreated, it can cause heart problems and dementia. If you get it when you are pregnant it can cause still birth or can infect the baby.