A protrusion in the middle of the rib cage in the chest may be caused by the following reasons: 1, local cartilage inflammation, this condition is usually caused by local injury or local friction often stimulates local cartilage aseptic inflammation, if, in addition to the protrusion, there are also local skin flushing, skin temperature, swelling and other symptoms of redness, swelling, heat and pain, it should be caused by costal chondritis; 2, local bony swelling The diagnosis can be confirmed by going to the hospital for a chest X-ray or a CT examination of the chest. If it is a localized costochondritis, you can take oral non-steroidal anti-inflammatory drugs and apply topical ointment to relieve swelling and pain, activate blood circulation and remove blood stasis, and the symptoms will gradually improve.