A microbial infection that can affect one or both of your lungs is known as pneumonia. This infectious condition can lead to inflammation of your lungs which get filled with fluid or phlegm and can make you sick. You will find it difficult to do your real-world activities with ease. Due to the weakened state of lungs people affected by a cold or flu are more likely to develop pneumonia. You may exhibit symptoms like fever chills and you may cough continuously. Moreover you will find it difficult to breathe. Microbes such as bacteria viruses and fungi can invite pneumonia.