Interstitial lung changes and interstitial pneumonia are not the same, in which interstitial lung changes can appear in the interstitial lung changes caused by pathogenic bacteria, while for interstitial pneumonia, it originates from interstitial fibrosis, the pathogenic bacteria mainly involves the interstitium of the lungs, there is no change to the lung parenchyma, and there is no reversibility of the rapid decline in lung function caused by interstitial pneumonia. For interstitial lung changes caused by common bacteria, some pathogenic foci of interstitial lung changes can be absorbed after symptomatic treatment with effective antibiotics, so there is no obvious decline in lung function after cure and it can be recovered. In the case of unexplained interstitial pneumonia, lung function is impaired very quickly and declines rapidly, which can lead to death.