Clinical Definition

A respiratory infection is considered an infectious disease, such as pneumonia, influenza and the common cold, which affects the respiratory tract. Respiratory infections may affect the upper respiratory tract, lower respiratory tract, or both.  A respiratory infection may be caused by a viral or bacterial pathogen and may range from mild to severe. Common causative agents of respiratory infections include coronavirus, influenza virus and rhinovirus.

In Our Own Words

A respiratory infection is an illness, which affects any part of the respiratory tract. It may be caused by bacteria or more commonly a virus. The respiratory tract is divided into the upper and lower tract. The upper tract includes the nose, voice box, sinuses and oropharynx. The lower respiratory tract includes the lungs, bronchial tubes and trachea.

“Upper” respiratory tract infections, however, don’t necessarily respect this anatomy, and they may spread to downward to cause a “chest cold,” which is common with certain viral infections, and does not require antibiotics.

Common infections of the upper respiratory tract include the common cold and sinusitis. Pneumonia is a common lower respiratory tract infection.  Usually infections involving the lower tract are more serious.