Answer:
blindness
deafness
paralysis
numbness
personality changes
poor muscle coordination
dementia
and also your risks of getting heart disease and a stroke and HIV/AIDS goes up
plus if you have syphilis and your pregnant then you can pass it on to your baby (congenital syphilis) for more information on syphilis itself please go to http://www.mayoclinic.com/health/syphilis/DS00374