Pneumonia is an acute inflammation of the lungs caused by different pathogens, and the degree of contagion varies between different types of pneumonia. The pathogens are usually bacteria, viruses, mycoplasma, chlamydia, etc. General pneumonia is not very contagious. When the body has normal resistance, these pathogens generally do not cause disease. However, some specific pneumonia, such as pneumonia caused by SARS virus, MERS virus, etc., can be highly contagious due to the infectiousness of these pathogens, which can easily lead to an outbreak. So whether or not pneumonia is contagious depends on the pathogen and the strength of its contagion.