Most of the people infected with novel coronavirus have dry cough, fever and malaise as their main clinical manifestations, but some of them have upper respiratory tract symptoms such as nasal congestion, runny nose, sore throat and muscle aches as their clinical manifestations. It is difficult to distinguish the symptoms of this part of the population from ordinary influenza symptoms, and it depends on whether it is a novel coronavirus infection. It depends on whether the patient has an epidemiological history, whether he/she has traveled to an infected area, whether he/she has been in contact with a person who has been diagnosed with novel coronavirus infection, and whether there is a familial aggregation of the disease around him/her. It is also important to look for low blood lymphocyte counts on laboratory tests, most notably if the nucleic acid detection test is positive. The diagnosis of a person with novel coronavirus infection can only be confirmed if the nucleic acid test is negative. A clinically diagnosed case can also be diagnosed if the nucleic acid test is negative and the clinical symptoms and laboratory tests are consistent with the typical symptoms of novel coronavirus infection.