The risk of intracranial hemorrhage is greatest within 24 hours, and most patients are now considered stable for about 1 week. The risk of rebleeding is greatest within 24 hours for subarachnoid hemorrhage, and decreases after 4 weeks. Most intracranial hematomas increase in the early stage of intracranial hemorrhage, generally within 3 hours of intracranial hemorrhage, 17%-38% of hematomas increase; 3-6 hours have 6%-16% hematoma increase, 6-24 hours have 10% hematoma increase, most hematomas are basically stable, the shorter the onset time, the greater the risk of hematoma increase, most cases hematoma increase occurs within 24 hours of intracranial hemorrhage. In addition, the risk period of intracranial hemorrhage is closely related to the amount and location of intracranial hemorrhage. A small amount of intracranial hemorrhage is generally stable for about 24 hours, while a large amount of intracranial hemorrhage is complicated by brain herniation, and the risk period may last for several weeks. Brainstem hemorrhage is so dangerous that death can occur within 48 hours. For patients with intracranial hemorrhage, timely dehydration and cranial pressure lowering treatment should be provided to reduce cerebral edema, adjust blood pressure, prevent further bleeding, reduce hematoma, promote neurological recovery and prevent complications.