2. Viral Pneumonia
Viral pneumonia is among the most common types of pneumonia, as Dr. Joseph Mercola says it accounts for approximately one-third of all cases. As its name implies, respiratory viruses—such as influenza, chickenpox, adenoviruses or respiratory syncytial—are what cause the condition.
Viral pneumonia is contagious, which the source says can be caught “via coughing, sneezing or touching an object that was contaminated by an infected person,” and it is characterized by swollen lungs and blocked oxygen flow.