The severity of the novel coronavirus varies slightly due to a variety of factors, including the number of viruses infected, the mode of infection, and individual differences. The elderly and patients with chronic underlying diseases have more severe symptoms and poorer healing, while pediatric cases have relatively mild symptoms. Most patients have fever, malaise and dry cough as the main manifestations, and a few patients have nasal congestion, runny nose, sore throat, diarrhea and other symptoms. Some patients with milder symptoms may only present with low-grade fever and mild malaise, without pneumonia. A few severe patients may develop respiratory distress a week after the onset of the disease, further developing into acute respiratory distress syndrome, septic shock and other serious symptoms.