The post-cerebral hemorrhage edema period usually peaks three to five days after the cerebral hemorrhage and begins to subside in about a week. However, for some patients, especially those with a large amount of cerebral hemorrhage, the edema period may last up to three weeks or even longer. The mechanism of cerebral edema is mainly due to the fact that after a cerebral hemorrhage occurs, the hematoma will compress the brain tissue around it, because brain cells have a very high demand for oxygen, and when it is subjected to localized compression, because the brain cells have to metabolize as well, it will lead to the brain cells not having enough oxygen to metabolize, which is called anaerobic metabolism. Anaerobic metabolism leads to acidosis of the cells, which leads to swelling of the brain cells. When brain cells swell, the most serious consequence is an increase in intracranial pressure. Therefore, the patient’s state of consciousness and head CT should be closely monitored, and appropriate measures for dehydration and lowering of cranial pressure need to be taken, e.g., through medication or surgery.