Pneumonia is the inflammation of your lungs caused by a bacterial or viral infection. During pneumonia your air sacs fill with fluids such as pus and become solid. It drastically hampers your ability to breathe and worsens your immune symptoms. Pneumonia can happen to anyone at any age. Babies under age 2 and adults over age 65 are at higher risk. What Causes Pneumonia? Pneumonia often occurs following an upper respiratory infection. Upper respiratory tract infections can result from colds or the flu. They’re caused by germs such as viruses fungi and bacteria. Germs can be spread in a variety