Most patients infected with novel coronavirus will have fever, dry cough, and malaise as the main manifestations, and some patients will have decreased or lost sense of smell and taste as the first symptoms, and a few patients may have nasal congestion, runny nose, conjunctivitis, sore throat, muscle aches, and diarrhea. Severe patients tend to develop respiratory distress or hypoxemia within a week or so after the onset of the disease. Severe cases can progress rapidly to acute respiratory distress syndrome, infectious shock, and even multi-organ failure. Patients with mild type can show hypothermia, mild malaise, and dysfunction of smell and taste without the manifestation of pneumonia, and a few patients can have no obvious clinical symptoms after infection with the virus. Infection with novel coronavirus can be classified into four types: mild cases, common cases, severe cases and critical cases. A small number of patients will be asymptomatic infections, and children’s infections are generally less symptomatic. Some children and newborns can have atypical symptoms, showing only gastrointestinal symptoms such as vomiting and diarrhea, or only poor response and shortness of breath.