Patients with asymptomatic infections usually do not show any symptoms or signs, and the types of asymptomatic infections are divided into hidden infections, pathogenic carriers and latent infections. 1. Occult infection: after the pathogen invades the human body, it only causes the human body to produce specific immune response, which will not cause or cause slight tissue damage, and the patient does not have any symptoms and signs, and even does not have any biochemical changes, and in order to diagnose the disease, it is necessary to do the relevant examination before being found, such as hepatitis B, poliomyelitis, etc.. 2. Pathogen carriage: pathogens enter the body and stay in the body to grow and multiply, but the body does not show any symptoms and signs. For example, hepatitis B, typhoid fever bacillus carries. 3. Latent infection: after the pathogen enters the body, the pathogen stays in a certain part of the body, the body can not remove the pathogen, but it will not cause clinical symptoms, latent infection generally does not exclude pathogens, such as chickenpox virus, herpes simplex virus, and so on. Asymptomatic infections can be diagnosed by pathogen testing, imaging, and blood tests. Asymptomatic infections should be actively consulted and treated in accordance with standardized treatment after diagnosis of the cause of the disease to avoid delays.