Bacterial or Viral Infections of the Respiratory Tract
Viral illnesses are the most common cause of upper respiratory symptoms. Symptoms of a viral illness often appear over several hours without prior illness. Common viral illnesses include colds and the flu (influenza).
Bacterial respiratory tract infections are less common than viral infections. Bacterial infections may develop after a viral illness such as a cold or the flu. Bacterial infections may affect the upper or lower respiratory system, and symptoms tend to localize to one area.
Antibiotics are effective against bacterial infections only after they have developed, so most doctors do not prescribe them until a bacterial infection is suspected or confirmed.
Primary Medical ReviewerWilliam H. Blahd, Jr., MD, FACEP - Emergency Medicine
Specialist Medical ReviewerDavid Messenger, MD
Current as ofAugust 21, 2015