Syphilis is a sexually transmitted infection (STI) that can cause serious health problems without treatment. You can get syphilis by direct contact with a syphilis sore during vaginal, anal, or oral sex. In other words, you can NOT get it by toilet seats, sharing clothing, eating together, etc. Syphilis can spread from a mother with syphilis to her unborn baby. During the first (primary) stage of syphilis, you may notice a single sore or multiple sores. The sore is the location where syphilis entered your body. These sores usually occur in, on, or around the penis, vagina, anus, rectum, mouth, lip, etc. During the secondary stage, you may have skin rashes and/or sores in your mouth, vagina, or anus. 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. Most people with untreated syphilis do not develop tertiary syphilis. However, when it does happen, it can affect many different organ systems. These include the heart and blood vessels, and the brain and nervous system. Tertiary syphilis is very serious and would occur 10–30 years after your infection began. In tertiary syphilis, the disease damages your internal organs and can result in death. A healthcare provider can usually diagnose tertiary syphilis with the help of multiple tests.