If the back of the head is a localized protrusion of the occipital area with pain, the first consideration is whether there is a cause of trauma, whether there is a touch or a fall. If there is a cause of trauma, it is obvious that the local subcutaneous hematoma and local mass are caused by trauma. Combined with whether there are cranial symptoms, combined with the assessment of the need for additional cranial CT to rule out intracranial injury. If there is no other cause, skin causes should be considered first, such as folliculitis of the head, and local inflammation of the skin, which may lead to masses and painful symptoms. Then there is the growth of superficial body swellings, which are manifested as localized protrusions. Because it is in the occipital region of the head at the back of the head, long-term pressure and irritation from a person’s sleeping position can also cause some painful symptoms. There are probably these causes, which need to be judged and analyzed in the context of the patient’s specific situation.