Few fibrous foci in the middle lobe of the right lung and the upper lobe of the left lung refer to the scarring that remains after a lung infection such as pneumonia or tuberculosis has been treated and the lesion has been absorbed. Interstitial lung tissue is composed of collagen, elastin, and proteoglycans. When fibroblasts are chemically or physically injured, they secrete collagen to repair the interstitial tissue, which in turn causes the lungs to fibrose with a few fibrous foci as a result of the body’s repair. In addition, some people may be due to environmental pollutants, such as haze, atmospheric pollutants, through the respiratory tract on the lungs to produce a certain stimulation of the fibrous foci left behind. This few fibrous foci will not affect the lung function and will not lead to other lesions in the lungs. Therefore, there is no need to worry and no need for treatment.