There is a big difference between Omicron and the common cold, and it is recommended to distinguish the two diseases by symptoms as well as nucleic acid tests. 1. Clinical symptoms: After being infected with Omicron, patients may have sore throat, cough, and some patients have fever, mainly moderate fever, and some patients have gastrointestinal symptoms, such as diarrhea, vomiting, nausea, etc. In severe cases, patients may have life-threatening symptoms. In severe cases of Omicron infection, it is possible to jeopardize the patient’s life. While the common cold manifests itself as sneezing, sore throat, and some patients have headache, runny nose and other symptoms. Patients with colds have more serious upper respiratory tract infections and mild systemic manifestations, and most patients’ colds are not life-threatening. 2. Nucleic acid test: Nucleic acid test can be used to determine whether the patient is infected with Omicron, and the diagnosis can be confirmed if the test result is positive. Chest CT of patients with flu has no obvious lesion changes, and the nucleic acid test is negative. It is recommended that patients suspected of having omicron infection should do a good job of personal protection to avoid the emergence of large-scale infection.