If the swelling of the head is caused by trauma, it may be caused by scalp hemorrhage. Cold compresses with ice should be applied at an early stage to prevent further expansion of the swelling, and a cranial CT examination should be performed at the hospital to find out if there are any lesions and hemorrhages in the skull, such as epidural hematoma or subarachnoid hemorrhage. Hot compresses can be applied after 24 hours to dissipate the masses early. It is possible that the mass is caused by a subscalp sebaceous cyst or a lipoma. A sebaceous cyst has a hard texture and a tofu-like substance inside, which can cause pain secondary to bacterial infection. If the bag is formed by a lipoma, the texture is softer and the boundary is clear, and if it needs to be removed, it can be removed surgically under local anesthesia.