Dear student.
Pneumonia is a type of lung infection which caused cough, fever and breathing trouble. Pathogens like bacteria or viruses cause pneumonia. As the pathogens enter the lungs symptoms of the disease starts. Pneumonia starts with cold or flu and gradually becomes severe with breathing trouble, chest pain, nausea and diarrhea. This disease in normal cases lasts for 2 to 3 weeks and can be treated at home. In aged persons and in infants pneumonia can be severe and may cause death also.
Regards.