Syphilis is a bacterial infection transmitted through anal sex, oral sex or arse play with an infected person. An untreated syphilis infection progresses through 3 stages. Stage 1: a painless red sore on your cock, balls, mouth, throat or arse that turns into a scab and then heals. Stage 2: rash on the palms of the hands, soles of the feet or other parts of the body, fever, swollen lymph glands, sore throat, headaches, weight loss, muscle aches and tiredness. Stage 3: damage to internal organs including the brain, nerves, eyes, heart, blood vessels, liver, bones and joints. This damage may be serious enough to cause death. Syphilis is easily diagnosed with a blood test and cured with antibiotics.