Syphilis can be detected by blood sampling, and syphilis is mainly determined by blood testing, which is called the laboratory diagnosis of syphilis. The RPR is an indicator of the activity of the disease and the effectiveness of the treatment, and the RPR titers range from low to high, such as 1:1 to 1:32. In addition to blood tests, dark-field syphilis tests can also be done, taking mucosal secretions and observing them under a dark-field microscope, which can also detect syphilis spirochetes. Then there is the combination of clinical determination, such as the patient can have erythema, papules, palmoplantar with copper-red patches, etc.