Common cold and influenza are viral infections of the upper respiratory tract. The common cold may be caused by a variety of viruses including the adenovirus, echovirus, parainfluenza virus, respiratory syncytial virus and rhinovirus. Influenza may be caused by the influenza viruses A, B or C. Common cold is an exogenous ailment with headache, nasal obstruction, aversion to wind and fever as its main manifestations. It often results from lowered superficial resistance and invasion of the exogenous pathogenic factors. It may occur in any season.
According to the difference in weather, pathogenic factors and body constitution, the manifestations can be classified into two types: wind cold and wind heat.
Infection from the common cold or influenza virus takes place through the upper respiratory tract and may occur in any season but it is more frequent in Winter or Spring. From the Chinese point of view, they can manifest with symptoms either of Wind-Cold or Wind-Heat.