The danger period of acute massive cerebral infarction is usually about 1 week, but some severe patients may reach about 2 weeks. Patients with acute massive cerebral infarction, because the brain tissue in the infarcted area may be edematous, when the edema reaches a certain degree, it will compress other brain tissues, leading to the formation of cerebral hernia, which will easily affect the life. Therefore, the danger period of acute massive cerebral infarction is usually about 1 week. In addition, if the patient develops worsening symptoms of cerebral infarction within 1 week, or for patients with cerebellar or brainstem infarction, the danger period will be prolonged accordingly, and may reach about 2 weeks. Patients with acute massive cerebral infarction should be hospitalized for active treatment during the danger period, and also need to be closely observed for changes in their condition.