It is impossible to compare which is milder and which is more severe, because any disease is both mild and severe, but if a patient with novel coronavirus pneumonia has a severe disease compared with tuberculosis, the severe disease of novel coronavirus pneumonia may change more rapidly and be more severe. Patients with severe cases of novel coronavirus pneumonia tend to develop respiratory distress and hypoxemia after a week, which can progress rapidly to acute respiratory distress syndrome, septic shock, uncorrectable metabolic acidosis and coagulopathy, and in rare cases, central nervous system involvement and ischemic necrosis of the extremities. Therefore, the mortality rate of critically ill patients with novel coronavirus pneumonia is higher and the disease is more severe.