A raised hard lump in the middle of the chest may be caused by keloid, or it may be caused by lipoma, sebaceous cyst, sternal fracture, breast disease and so on. 1. Keloid: if the patient’s chest has been traumatized or skin allergies after acne, in the process of recovery due to excessive proliferation of scar tissue, protruding from the surface of the body to form a keloid, usually manifested as a touch of hardness, accompanied by itching, light pressure pain of the swelling. 2. Lipoma and sebaceous cysts: benign lesions, sebaceous cysts protrude on the surface of the skin, most obvious in the neck and chest and back, accompanied by pain and pus phenomenon in case of infection; lipomas are generally smoother, clear boundaries, protruding on the surface of the skin, and can be pushed. 3. Sternum fracture: a raised hard lump on the chest may be a fracture of the sternum and protrude from the skin surface, if the chest has suffered violent injuries, there is a greater possibility of a hard lump on the chest, the need for patients to go to the hospital to prevent misalignment. 4. Breast diseases: such as breast hyperplasia, breast fibroadenoma, breast cancer, etc., the same will appear on the chest (on the breast) of the hard lumps, found that should be timely consultation, clear cause of the disease after treatment. There are many reasons for a raised hard lump in the middle of the chest, so it is recommended that patients seek timely medical attention to clarify the cause of the disease and follow the doctor’s instructions for standardized treatment.