Repeated multiple tuberculosis skin test, mainly tuberculosis has a latent period. Tuberculosis is a chronic and slow-onset infectious disease that is more likely to occur in adults. Most patients do not have obvious clinical symptoms after the initial infection with Mycobacterium tuberculosis, and only gradually feel uncomfortable as the disease develops and the incubation period ends, which lasts for 4 to 8 weeks. Tuberculosis skin test is also known as tuberculin test or PPD test, the significance of aiding in the diagnosis of tuberculosis, for the results of the patient is negative, does not mean that completely not infected with tuberculosis bacilli, there may be in the incubation period of the patient, so you need to repeat several times to carry out the tuberculosis skin test. It is recommended that patients follow the doctor’s instructions for examination and treatment, and the doctor will combine the symptoms, signs, imaging and laboratory data to make a comprehensive analysis and clarify whether they are suffering from tuberculosis.