Syphilis is caused by infection with the syphilis spirochete and is mainly transmitted through sexual contact, mother-to-child, and blood. Syphilis is a sexually transmitted disease (STD) caused by infection with the syphilis spirochete. The only source of syphilis is the patient with syphilis, whose skin lesions, blood, semen, and breast milk contain the syphilis spirochete, and whoever comes into contact with these body fluids of the patient with syphilis is likely to be infected. Syphilis is mainly transmitted through sexual contact, mother-to-child transmission and blood. Unprotected sex, sexual activity, promiscuity or sharing needles will increase the chance of getting syphilis. If the patient has the above high-risk behaviors, it is recommended to actively consult a doctor to improve the relevant examination to clarify the diagnosis, so as to avoid delaying the condition.