An upper respiratory infection (URI), also known as the common cold, is one of the most common illnesses, leading to more doctor visits and absences from school and work than any other illness every year. It is estimated that during a one-year period, people in the United States will suffer 1 billion colds.
Caused by a virus that inflames the membranes in the lining of the nose and throat, colds can be the result of more than 200 different viruses. However, among all of the cold viruses, the rhinoviruses and the coronaviruses cause the majority of colds.
|Low or no fever||High fever|
|Sometimes a headache||Commonly a headache|
|Stuffy, runny nose||Sometimes a stuffy nose|
|Mild, hacking cough||Cough, may progress|
|Slight aches and pains||Often severe aches and pains|
|Mild fatigue||Fatigue, may persist|
|Sore throat||Sometimes a sore throat|
|Normal energy level||Exhaustion|