Head swelling and pain on impact may be related to bleeding of brain tissue, soft tissue hematoma in the head, skull fracture and other reasons. 1. Brain hemorrhage: after a severe impact on the head, bleeding of brain tissue in the skull may occur, which may cause head swelling and pain. 2. Head soft tissue hematoma: after the head is hit, the head skin, muscles and other soft tissues may bleed to form a hematoma, resulting in head swelling and pain. 3. Skull fracture: after the head is hit, skull fracture can occur, which may cause intracranial pressure to rise, resulting in head swelling and pain. It is recommended to go to regular hospitals for timely consultation, clear diagnosis, and standardized treatment under the guidance of doctors to avoid delaying the condition.