Stage III syphilis and stage I syphilis and stage II syphilis are the same test, as long as the diagnosis of stage III syphilis, need to be actively screened for complications, active treatment to control complications. 1. Syphilis detection method: do syphilis pale spirochete antigen test and syphilis serologic test examination. If the patient has related neurological symptoms or the treatment is ineffective, the patient needs to carry out cerebrospinal fluid examination and so on. 2. Complications: patients with stage III syphilis belong to advanced syphilis, usually patients with syphilis has been more than two years, including visceral syphilis, neurosyphilis and so on. Visceral syphilis, indicating that syphilis has invaded the cardiovascular and cerebral vessels. Patients with stage three syphilis need to be individualized according to individual symptoms, under the guidance of a professional doctor, according to the specific conditions, to develop individualized diagnostic and treatment programs, so as not to delay the condition.