Pneumonia is an infection in one or both lungs caused by bacteria fungi and viruses. The infection causes inflammation of the air sacs in your lungs commonly known as alveoli. Fluid or pus in the alveoli can cause difficulty in breathing as well as fever cough and chills. Pneumonia occurs commonly in infants and older people who are above 65 years as they have a weak immune system. It is a life-threatening condition and therefore you must immediately see a doctor if you experience its symptoms which include chest pain shortness of breath cough fatigue fever and chills nausea and