If a patient with cerebral infarction suddenly faints, it is considered that the site of cerebral infarction has affected the superior reticular activation system of the brainstem, or the middle cerebral artery or the basilar artery of the brain has suddenly occluded, resulting in severe cerebral blood supply deficiency, then the patient will suddenly faint. If the infarct is large or if the infarct is in the lower medulla of the brainstem, the patient may experience sudden respiratory distress and sudden death. If the infarction is in the cerebral hemisphere, severe cerebral edema may occur, and then the patient may become unconscious, have dilated pupils, and have paralysis of the limbs, incontinence, and other symptoms. If the patient suddenly faints because of cerebral infarction, we must actively look for the cause and then treat it. If it is considered to be caused by cerebral edema, then we should promptly do craniotomy to save the patient’s life.