Syphilis is a common sexually transmitted disease ( STD ). It’s easily cured but can be serious if it’s not treated. This STD develops in four stages. Symptoms in the first two can be so mild.

Overview Syphilis is a sexually transmitted infection (STI) that causes sores and a skin rash. It can be life-threatening without treatment. What is syphilis? Syphilis is a sexually transmitted infection (STI) that spreads when you have vaginal, anal or oral sex with someone who has the infection. A bacteria causes it.