A hard bag behind the head that hurts when pressed is seen for the following reasons: 1. Patients should be asked if there is any trauma, especially a history of head trauma. If the head occipital landing, easy to appear subscalp hematoma, and the emergence of a hard bag a painful feeling when pressed. 2, the back of the head long hard bag, to check the patient has no surrounding redness or swelling or surrounding skin heat. Patients with folliculitis are prone to inflammatory reactions around them because of blocked pores, which manifests itself as a painful sensation when a hard pack is pressed. You can go to the hospital for routine blood measurement to find out if there are elevated white blood cells. 3. pay attention to whether there is a decrease in body resistance, septic infection can cause scalp hard packs.