Sudden swelling of the chest is very likely to be caused by local tissue lesions, and the common causes of this situation include infection, tumor and trauma. 1. Infection: Chest infection causes suppurative lesions, local pus accumulates obviously, which will lead to swelling in a short time, at this time, patients usually have fever, redness and swelling in the swollen area. 2. Tumor: the tumors that increase in a short period of time commonly include lobular tumors, which belong to fibroepithelial tumors, and the cell proliferation in a short period of time will have corresponding changes. 3. Trauma: after trauma, it will lead to edema, oozing and bleeding of the surrounding soft tissues, which will lead to the manifestation of sudden swelling of chest, and this kind of patients usually have the history of trauma. Sudden swelling of the chest, accompanied by obvious pain and discomfort, need to consult a doctor in time for observation, after diagnosing the specific cause of the disease, under the guidance of the clinician for standardized treatment.