Normal people usually do not have proliferative foci in the lungs, and the presence of proliferative foci in the lungs is most often considered to be the formation of fibrotic proliferative foci during the repair of lesions that once existed in the lungs. Lung proliferative foci refers to the patient in the chest CT, chest radiographs, chest X-ray and other imaging examinations, the lungs will appear uneven, high density of fibrosis foci, and the fibers are mostly striated, which suggests that the patient’s lungs have old lesions, so normal people usually do not have proliferative foci in the lungs. Patients with proliferative foci in the lungs is mainly due to the lungs had inflammatory lesions or injuries, and these lesions in the repair process and the surrounding fibrous tissue, connective tissue proliferation to form fibroproliferative lesions. Generally, normal people will not have lung proliferative foci, if the patient’s lung proliferative foci are relatively limited and have little effect on lung function, they can be left untreated. If the patient’s lung proliferative foci are relatively large in scope and affect the ventilation function, the patient needs to consult a doctor in a timely manner under the guidance of the doctor to choose the appropriate measures for treatment.