Novel coronavirus pneumonia is an infectious disease caused by a novel coronavirus. It can be clinically classified as mild, common, severe, and critical. Mild novel coronavirus infections tend to have mild clinical symptoms, which may include cough, fever or no fever, and may be similar to the course of a mild cold, but such patients are still infectious; the common type mainly presents with cough, fever and dyspnea, and dyspnea is mainly due to the virus affecting the lungs and causing problems with gas exchange in the lungs; heavy and critical patients often have a combination of severe infection, organ failure, and acute respiratory distress syndrome on top of the disease. Severe and critical patients often have severe infections and organ failure, including acute respiratory distress syndrome, in combination with the disease. These patients often require more complex treatment, even ICU admission. The severe and critical types are the more dangerous types. Content source: Dr. You Lai