Symptoms of C.N.C.P. have more similarities with those of cold and flu, and it is difficult to differentiate them based on the symptoms alone. Pathologic tests (e.g., nucleic acids, antigens, etc.) are needed to clarify the situation. Croup is mainly characterized by fever, dry cough, fatigue, loss of smell and taste, and in severe cases, chest tightness, shortness of breath, and difficulty in breathing, etc. Common colds and influenza may have similar symptoms, and common colds may also include sneezing, nasal congestion, and runny nose. The biggest difference between the new crown pneumonia symptoms and the cold and flu is that the infecting pathogen is different, manifested as nucleic acid, antigen test results are different, for the new crown virus nucleic acid or antigen check, the new crown infected people will be positive, while the cold and flu body does not have the new crown virus, the check will be negative.