Viral respiratory infections are group of illnesses caused by viruses, affecting the upper, the lower or both parts of the respiratory tract.

They are generally classified as clinical syndromes such as:

  • Common cold
  • Bronchiolitis
  • Croup
  • Influenza-like illness
  • Pneumonia

Viral respiratory tract infections are typically divided into:

  • Upper respiratory tract infections: Symptoms occur mainly in the nose and throat. Viral upper respiratory tract infections may occur at any age and include the common cold and influenza.
  • Lower respiratory tract infections: Symptoms occur in the windpipe, airways, and lungs. Viral lower respiratory tract infections are more common among children and include croup, bronchiolitis, and pneumonia.

Children sometimes have infections involving both the upper and lower respiratory tracts.

More than 200 types of viruses can cause respiratory infections

Although specific viruses commonly exhibit their own characteristic clinical manifestations, each can cause many of the viral respiratory syndromes