The common cold is caused by a virus that infects the upper respiratory tract causing local inflammation. it is clinically called coryza, which comes from the greek for

The word Coryza comes from Greek word "kóruza" which means "nasal mucus".

The infection of the upper respiratory tract by the virus will induce an inflammatory reaction that will lead to secretion of thin watery mucus. The patient will have a runny nose and/or nasal congestion with loss of ability to smell.