Syphilis (pronounced siff-eh-lis) is a bacterial infection that is sexually transmitted. It progresses in distinct stages. The disease is curable and progression is preventable if syphilis is caught early and treated. But if it isn't treated, it can cause serious damage to the cardiovascular system and brain and lead to blindness and nerve problems.
Syphilis is often called "the great imitator," because its signs and symptoms are indistinguishable from those of other diseases.