Syphilis can be detected visually by the appearance of lesions on the body surface. Syphilis can be characterized as stage 1, stage 2 or stage 3, and the symptoms vary from stage to stage. 1. Stage I syphilis: The symptoms include a hard chancre (a painless ulcer) on the skin of the genitals and enlarged lymph nodes around the genitals, with no pain or tenderness. 2. Stage 2 syphilis: Syphilis rash appears on the skin and mucous membranes. Rash generally no self-conscious symptoms, the number of more, mostly symmetrical distribution, often generalized; may also appear worm-eaten hair loss. 3. Stage III syphilis: often in the head, face, shoulders, back, manifested as a cluster arrangement of copper-red nodules, can be fused into a block, can evolve into a kidney-shaped or horseshoe-shaped nodules, syphilis accumulation of the nervous system, neurological symptoms can occur. Some patients may also have no obvious clinical manifestations. It is recommended that patients with high-risk behaviors who are worried about syphilis infection should go to a regular hospital in time to get a clear diagnosis and avoid delaying their condition.