Causes
As mentioned earlier, the infection could be viral, bacterial or fungal by nature. In some cases, parasitic infection is also detected. Often, people develop pneumonia after they have had an infection such as cold or flu. To add to this, chronic conditions such as cancer, diabetes, asthma, and bronchitis to name a few, tend to weaken the immune system. And so people having any of these conditions, are more susceptible to contract bilateral or normal pneumonia.