Symptoms of syphilis in adults can be divided into three stages:
Stage 1 (primary syphilis)
Symptoms of syphilis begin with a painless but highly infectious sore on the genitals or sometimes around the mouth. If somebody else comes into close contact with the sore, typically during sexual contact, they can also become infected. The sore lasts two to six weeks before disappearing.
Stage 2 (secondary syphilis)
This stage usually starts with a rash on one or more areas of your body. The rash can show up when your primary sore is healing or several weeks after the sore has healed. Other symptoms you may have can include fever, swollen lymph glands, sore throat, patchy hair loss, headaches, weight loss, muscle aches, and fatigue. Without the right treatment, your infection will move to the latent and possibly late stages of syphilis.
Stage 3 (tertiary syphilis)
Symptoms of the late stage of syphilis include difficulty coordinating your muscle movements, paralysis (not able to move certain parts of your body), numbness, blindness, and dementia (mental disorder). In the late stages of syphilis, the disease damages your internal organs and can result in death.