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    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.

    The most common sites of bacterial infections in the upper respiratory system are the sinuses and throat. Pneumonia is the most common bacterial infection of the lower respiratory system.

    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.

    ByHealthwise Staff
    Primary Medical ReviewerWilliam H. Blahd, Jr., MD, FACEP - Emergency Medicine
    Specialist Medical ReviewerDavid Messenger, MD

    Current as ofSeptember 9, 2014

    WebMD Medical Reference from Healthwise

    Last Updated: September 09, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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