Clinical Definition

Bacterial pneumonia is an acute or chronic infection of one or both lungs, with inflammation and varying degrees of fluid filling the air sacs (alveoli) causing respiratory dysfunction. Some types of pneumonia can be seen on chest x-ray as areas of density in the infected parts of the lungs.

In Our Own Words

Pneumonia is an infection and inflammation of the lungs that can be quite serious, and bacterial pneumonia tends to be the most serious kind. Bacteria can’t always survive in the lungs due to our defense mechanisms, but many pathogens have strategies to overcome our defenses. Streptococcus pneumonia, or pneumococcus, is one of these. The influenza virus can also pave the way for bacterial pneumonia quite efficiently. The infection causes lungs to swell and the air sacs to fill up with fluid, which makes it harder to breathe and get enough oxygen. Complications involving the heart and lungs can occur, and bacteria in the blood (bacteremia) can also be associated with pneumonia. Healthy individuals typically recover quickly when treated with antibiotics. Cough, fever, shaking chills, and shortness of breath are common in bacterial pneumonia. If you smoke, are over the age of 65, are already sick or have a weakened immune system, you are at higher risk. Pneumococcal vaccine and influenza vaccine are both potentially protective against pneumonia.