What are the Differences Between Pulmonary Fibrosis and Pulmonary Fibrotic Lesions?

Apart from lung cancer, there are many other lung diseases, such as pulmonary fibrosis and fibrotic foci. These two diseases have significant differences and vary in severity. Generally, pulmonary fibrosis is much more severe than fibrotic foci. There are various causes of pulmonary fibrosis, while fibrotic foci are more often caused by pathological reasons, which require patients' attention. Localized fibrotic foci are mostly sequelae of infection. Localized fibrotic foci are actually a kind of scar. Most scars on the skin are caused by trauma, while most scars on the lungs are caused by infection. Infection is likely to leave necrosis in the lungs. After the infection is eliminated, the body will mobilize fibroblasts around the necrosis to secrete collagen fibers and other substances into the void to fill it. These collagen fibers are the cause of fibrotic foci formation. Fibrotic foci changes are mostly limited to one segment of one lung, which is related to the fact that infections mostly do not invade both lungs. However, there are also some infectious lesions, such as SARS infection, which can leave extensive fibrotic changes in both lungs after recovery. On the other hand, interstitial lung diseases usually manifest as symmetrical and multiple reticulated changes in both lungs, even forming honeycomb-like lung changes. In terms of their impact on lung function, fibrotic foci changes have a relatively small effect. Due to the limited scope of fibrotic foci changes, they have minimal impact on lung function and generally do not cause significant lung function decline. In contrast, bilateral lung fibrosis has a certain impact on lung function even in the early stages of the disease, and may lead to severe hypoxia and type I respiratory failure, even threatening life, in the end stage of the disease.