Syphilis is a centuries-old disease, affecting mainly men. Syphilis is not as common as it used to be, thanks to antibiotics, however it is begining to make a comeback with antibiotic resistant strains. Syphilis has two stages of development. The first is indicated by one or more firm, round, painless sores which appears about 3 weeks after infection. Left untreated, the sore heals in 3-6 weeks, but may lead to a second stage of infection, marked by an itchless rash accompanied by possible fever, swollen lymph glands, sore throat, patchy hair loss, weight loss, headaches, muscle aches and fatigue. Other symptoms may include uncoordination, paralysis, numbness, gradual blindness and severe confusion.

Syphilis can usually be treated with antibiotics, however damage caused by Syphilis may or may not be able to be repaired.