What is the ? A is a contagious viral infection of the upper respiratory tract. The symptom of a are stuffy nose, congestion, runny nose, fever, headache, cough, sore throat or fatigue in the body. A could have one or a few of these symptoms. What are the causes of the ? Colds are caused by one of hundreds of common viruses that can easily be transmitted from person to person. In this essay we are going to emphasize on six of the possible causes of a : Virus infection, lack of specific antibody, acute stress, chronic stress, increased human ....