Tertiary syphilis mainly occurs two to three years, or even five to ten years or longer, after infection. The primary skin manifestations are gummas, which often occur on the extensor side of the lower legs, and can present as ulcerations, erosions, nodules, and hyperplasia. It may also involve bones, joints, the heart, and blood vessels. The main manifestations include aortitis, aortic valve insufficiency, and aortic aneurysms. When the nervous system is involved, it can present as spinal tuberculosis and general paralysis, which are symptoms of paralytic dementia. The diagnosis of tertiary syphilis requires serological tests and cerebrospinal fluid analysis. The treatment involves primarily penicillin and benzathine penicillin, with erythromycin or tetracycline as alternatives for patients allergic to penicillin, and requires a longer course of treatment.