Colds are virus-infected diseases in the upper respiratory tract and classified as common cold and influenza. Common cold, usually mild, results from rhinovirus infection and is characterized mainly by nasal symptoms. With a high morbidity and repeated infection tendency, common cold may occur all the year round but mostly in winter and spring. But influenza, usually widespread, is due to influenza virus infection and has pronounced systemic toxic symptoms.
Colds fall into the categories of "shang feng "(common cold), "shi xing gan mao" (influenza), etc. in TCM according to the clinical manifestations. The chief pathogenic factors are pathogenic wind and pestilential toxicity and the main pathogenesis includes pathogenic factors invading the body surface and disharmony between weifen and the exterior. The syndrome mostly seen is exterior excess of the lung and weifen.
