A big bump on the brain and a swollen eye are related to subcutaneous hematoma, brain injury, orbital fracture and so on. 1. Subcutaneous hematoma: hematoma will be formed when local capillaries rupture as a result of a bump on the brain and blood leaks out of the blood vessels and accumulates in the skin and under the skin. Subcutaneous hematoma is the main cause of swelling in and around the bumped area, and may be accompanied by pain and other uncomfortable symptoms. 2. Brain injury: When the external force on the head causes brain tissue injury, the patient may suffer from concussion, cerebral contusion, intracranial hematoma, which may be manifested as swollen eyes, nystagmus, headache, dizziness, nausea and vomiting, tinnitus, palpitation, memory loss and so on. 3. Orbital fracture: Orbital fracture is related to direct violence and indirect violence. When orbital fracture is caused by a foreign object knocked on the brain, the patient may have swollen eyes. Some orbital fracture patients may also have subcutaneous bruising, limited eye movement, diplopia, vision loss and blindness. It is recommended that those who have swollen eyes after knocking a big bag on the brain should consult a doctor for examination and follow the doctor’s instructions after clarifying the cause of the disease, and should not use medicines or prescriptions indiscriminately on their own before the cause of the disease is clarified.