High density shadow of ribs means that there is an abnormal displacement at the ribs in the imaging examination, which may be physiological, or it may be caused by tuberculosis, tumor or fracture healing. 1. Physiological: In the process of growth and development, the ossification of ribs is not uniform, and there is a situation that the density is higher in some places, for example, there is calcification in some parts of ribs, and the imaging examination will show high-density shadow. 2. Tuberculosis: when Mycobacterium tuberculosis attacks the ribs and forms tuberculosis foci, such as caseous necrosis, it may also show high density shadow of ribs. 3. Tumor: including benign tumor and malignant tumor, it can be initially judged according to its morphology, whether there are abundant blood vessels penetrating, etc. If the diagnosis needs to be confirmed, it is necessary to do pathological examination. 4. Fracture healing: in patients with a history of rib fracture, the bone seam may gradually form a high-density shadow during the healing process. Patients who find high density shadows on the ribs should actively search for the causes, and if they are caused by pathological factors, they need to be actively treated.