Some patients have bony protrusions in the mastoid area, and there are several reasons for this: First, the patient is too thin, the mastoid area itself has bony protrusions, and if the patient is too thin, it will become more obvious. Second, it may be caused by genetic factors, some patients may be congenitally protruding in this area. Third, it may also be caused by trauma, if the patient has previous contusions, fractures and other injuries here, it may cause excessive bone growth in this area after its recovery, and then lead to its protrusion. Fourth, it may also be caused by inflammation and infection in this area, which may also cause abnormal calcium deposits in this area during the process of recovery from the above-mentioned diseases, leading to its protrusion.