The bone in front of the chest is high and low on one side, which may be caused by the following reasons: First, it may be caused by the old injury of the thorax. For example, if the patient had multiple rib fractures on one side of the thorax in the past, after recovery, the thorax may be left relatively concave. This results in bilateral asymmetry. Second, it may be caused by congenital bony deformity. For example, if the patient has congenital thoracic deformity or scoliosis, it may lead to this bilateral asymmetry. Third, it may be caused by a large amount of pleural effusion on one side. For example, if the patient has a large amount of pleural fluid on one side of the chest, it is possible that one side of the chest is fuller and more prominent than the opposite side. Fourth, there may also be a side of the thorax caused by long-term pressure. For example, if the patient sleeps in a prone position for a long time, it may cause long-term pressure on one side of the thorax, which may lead to a more concave thorax on this side. There will be a very obvious asymmetry of the thorax on the chest side.