Asymptomatic infected persons may remain asymptomatic or may develop symptoms at a later stage. There are two types of asymptomatic infected patients: those who have no clinical symptoms during the whole course of the disease, or those who have only mild symptoms; and those who are asymptomatic during the incubation period of the virus, but with the continuous replication of the virus and the progressive development of the disease, symptoms of the infection may appear at a later stage. The emergence of asymptomatic infected patients is generally associated with a strong autoimmune function and a small number of viruses invading the body. After the virus enters the body, it multiplies and continues to violate the body’s immune system. Some patients’ immunity gradually decreases, and they may develop symptoms of viral infection such as fever, cough, nasal congestion, runny nose, chest pain, etc. However, for patients with a strong constitution, they may still not show obvious clinical symptoms. Asymptomatic infected patients may also be infectious to some extent, so they need to be observed and treated immediately after diagnosis. Patients can increase physical activity during this period to strengthen their body to reduce the possibility of disease exacerbation. In the case of New Coronavirus infection, for example, patients who still show positive nucleic acid test results after the 14-day incubation period can go to the hospital for further improvement of chest CT examination. Patients without abnormalities also need to continue isolation and observation until the nucleic acid result is negative.