The main symptoms of contusion of the rib cartilage are local pain and redness. This is mainly due to rupture and bleeding of small capillaries after the contusion, blood exudation and inflammatory edema, which leads to a localized redness and swelling. In addition, there is significant pain because the injury irritates small nerves. After the injury, sterile inflammation develops, and the inflammatory metabolites inside the lesion stimulate the peripheral nerves, resulting in significant pain. Inflammatory edema can also form after the injury, and these edemas can cause compression of the surrounding tissues and peripheral nerves, which can also cause significant pain. In addition, compression of these lesions and contusions with hand pressure can also cause increased pain, and coughing and deep breathing with the rise and fall of the thorax can stimulate the injury site and cause increased pain.