There are differences between syphilis and AIDS in terms of pathogens, clinical symptoms, and prognosis. 1. Pathogen: syphilis is a chronic sexually transmitted disease caused by the syphilis spirochete that invades multiple systems; AIDS is a systemic immunodeficiency syndrome caused by human immunodeficiency virus infection. 2. Clinical symptoms: the clinical symptoms of syphilis are skin and mucous membrane damage in the early stage, and in the late stage, it can cause bone, heart, central nervous system and other organs and tissues; AIDS can cause immunodeficiency, which leads to the decline of immunity, and thus various opportunistic infections and tumors appear. 3. Prognosis: most syphilis can be cured after active treatment, and the organic damage is irreversible; while AIDS can only control the condition, and requires lifelong medication, and cannot be cured. Syphilis and AIDS are basically similar in the way they are transmitted, through sexual contact, blood and mother-to-child transmission. It is recommended that patients make the distinction under the guidance of a doctor to avoid self-diagnosis errors.