A minimum of about 3 weeks need to elapse during the cerebral hemorrhage danger period. This is because within 3 weeks, patients with brain hemorrhage are at risk for rebleeding, cerebral edema, and related complications. First, rebleeding occurs mainly within 72 hours after the hemorrhage, and the risk of rebleeding is greatly reduced if it occurs after 72 hours. Secondly, the second dangerous period after a cerebral hemorrhage is the cerebral edema stage. Cerebral edema is mainly due to the pressure of hematoma on the surrounding tissues after cerebral hemorrhage, which leads to ischemia and hypoxia of brain cells, thus swelling occurs. Cerebral edema occurs 3-5 days after hemorrhage and begins to subside in about 1 week. For patients with large amounts of bleeding, cerebral edema may last up to about 2 weeks in some patients. Finally, there is the stage of complications, which are mainly lung infections, intracranial infections and deep vein thrombosis of the lower extremities. The complication is good for about 3 weeks, so the cerebral hemorrhage risk period takes about 3 weeks.