Respiratory viral diseases are infectious. It generally infects the upper and lower parts of a person's respiratory tract.

Examples of respiratory diseases are:

Flu
Respiratory syncytial virus infection
Common cold
Parainfluenza virus infection
Adenovirus infection
SARS (severe acute respiratory syndrome)
Clinical Manifestation:

Runny or stuffy nose
Fever
Coughing or sneezing
Body aches
Transmission:

Respiratory viruses are transmitted via droplet infection (coughing or sneezing). A person may catch the infection if any person with viral infection sneezes or coughs near them, and unknowingly they inhale these droplets. Contaminated Objects, like tabletops, doorknobs, and one's own daily use items, can also transmit viruses if we use them and then touch our eyes or nose.

Treatment

These types of viral diseases cure on their own. But OTC (over-the-counter) drugs such as decongestants, antitussives, and analgesics help to lessen the symptoms.

Additionally, Tamiflu is an antiviral medicine that is recommended for a person suffering from the flu.

Precautions:

Maintaining good personal hygiene is the best way to prevent respiratory viral diseases
Wash hands frequently and cover your mouth while you're coughing or sneezing
To avoid interactions with the person showing symptoms of respiratory diseases