Talking about the principle of cold from a scientific point of view.

Bacteria or pathogens carrying cold virus enter the human body through the respiratory tract and multiply and infect the human body. This harmful virus is generally called antigen. Although the human body can produce corresponding antibodies to inhibit it, it will cause different degrees of reactions due to the level of human immunity and the strength of antigens.

When the virus enters the human body, there will be various uncomfortable situations before catching a cold, which represents a sign.