A sharp bilateral rib-diaphragm angle is normal and represents the absence of pleural effusion. Rib-diaphragm angle is one of the descriptions in chest radiographs, which is the angle between the diaphragm and the ribs on both sides and the thorax. Normally, the rib-diaphragm angle is an acute angle with a curvature, so a sharp rib-diaphragm angle bilaterally means that there is normal fluid inside the thoracic cavity. If the angle of the rib diaphragm becomes blunt, it means that there is fluid in the chest cavity, which can be seen in tuberculous pleurisy, pneumonia, tuberculosis, lung cancer, etc. The angle of the rib diaphragm disappears when there is serious fluid in the chest cavity. In addition to pleural effusion, the obtuse rib-diaphragm angle can also be seen in thickening of the costal membrane and liver tumors. It is necessary to find out the cause of the disease in time, and target treatment. Bilateral sharp rib diaphragm angle is not abnormal, no need to worry, regular physical examination can be. If there is any symptom, please consult the doctor in time to avoid delaying the condition.