(3) Common Cold Explanation: Common cold is a viral infectious disease of the upper respiratory tract which affects primarily the nose. Symptoms include coughing, sore throat, runny nose, and fever which usually resolve in seven to ten days, with some symptoms lasting up to three weeks. Well over 200 viruses are implicated in the cause of the common cold; the rhinoviruses are the most common. It is the most frequent infectious disease in humans with the average adult contracting two to three colds a year and the average child contracting between-six and twelve.