There are various reasons for a hard lump in the middle of the rib cage, and the common reasons are usually caused by excessive osteophytes, local tumors, local inflammation and so on. 1. Excessive osteophytes: it may be caused by old fracture due to old injury, due to healing, there will be local bone scab, also manifested as local bulging lumps, there will be slight pain. 2. Local tumor: occupying lesions, tumors occurring in subcutaneous tissues or muscles, such as lipoma, generally benign, mainly manifested as local tumor elevation, soft texture, no redness and swelling, no or light pressure pain; if it is intercostal neurinoma, it may compress the nerves, causing local numbness and discomfort. 3. Local inflammation: such as costochondritis, due to inflammation and swelling, a hard lump will be formed, which will cause local pain, numbness and affect the patient’s breathing. There are many reasons that lead to a hard lump in the middle of the rib cage, it is recommended to go to the hospital in time to find out the reason and treat the symptoms.