Common pneumonia is not contagious because the decision of whether pneumonia is contagious is mainly related to the different pathogenic microorganisms that infect it. Usually, the main infecting microorganisms in common pneumonia are bacteria, mycoplasma and chlamydia, and in some people, viral infections cause it. But these viruses are often not contagious, only a few viral pneumonia, such as SARS virus, the Middle East respiratory syndrome virus and the new coronavirus that appeared in 19 years, this virus infection of the human body will appear contagious, and also the phenomenon of human-to-human transmission. Therefore, there is no need to be overly worried or nervous about common pneumonia, as long as you do a good job of general health protection and active treatment.