Some cerebral infarction occurs after hospitalization more and more serious and infarction area expansion, the emergence of complications and poor general condition, etc., belong to the normal process, the serious cases can be directly life-threatening. 1. Expansion of infarction area: if there is a watershed infarction with large vessel stenosis, the infarction area can be further expanded and the clinical symptoms further aggravated if the stenosis is not relieved in time. 2. Complications: the primary infarction area is not enlarged, the cerebral edema spreads, the edema zone expands, and gradually aggravates the degree of neurological deficit; for example, cerebral edema secondary to large cerebral infarction. The condition can be aggravated if hemorrhage occurs during thrombolytic therapy for cerebral infarction transformation, or if vascular recanalization fails or is completely occluded due to complex vascular conditions during interventional surgery. 3. General status: cardiopulmonary function, changes in water, electrolyte or acid-base balance, and infections can interfere with metabolism and lead to aggravation of neurological deficits. Examples include cardiopulmonary arrest and pneumonia. However, if the patient does not receive treatment, the condition will deteriorate rapidly and become life-threatening, so it is recommended that the patient actively cooperate with the treatment.