Intracerebral hematoma formed by brain hemorrhage will stimulate brain tissue and cause cerebral edema. Cerebral edema is not serious in the early stage of cerebral hemorrhage, but it will gradually worsen with the passage of time, and the peak of cerebral edema will be formed 5-7 days after cerebral hemorrhage, so the condition of cerebral hemorrhage will be the most serious in the 5-7 days after hemorrhage. In severe cases, the patient will be in coma, and even need emergency craniotomy hematoma removal, plus decompression of the skull bone flap to get through the peak of cerebral edema. The reason for the formation of cerebral edema is that after cerebral hemorrhage, the red blood cells within the hematoma slowly crack and split over time, and the hemoglobin and other products of red blood cell cracking will stimulate the surrounding brain tissue, causing edema and swelling of the brain cells causing cerebral edema.