Pneumonia
By Susan Chow, PhD, ELS
Pneumonia is an acute respiratory infection of the lungs. In patients with pneumonia, the alveolar sacs of the lungs become inflamed and fill with fluid or pus. The pneumonia infection can occur in a single lobe of one lung (lobar pneumonia), or it can affect both lungs (bronchial pneumonia).
Since the alveolar sacs are responsible for oxygen exchange, buildup of fluid or pus within these structures can prevent proper filling with air and lead of inefficient levels of oxygen reaching the blood. Because of this, pneumonia can be particularly dangerous in children under age 2, adults over age 65, people with a weakened immune system, or those with chronic lung diseases such as COPD and asthma.
https://www.news-medical.net/health/Pneumonia.aspx
