Patients with stroke, if experiencing cerebral hemorrhage, extensive cerebral infarction, or cerebral embolism, can develop cerebral edema. In such cases, it is necessary to use mannitol for dehydration to reduce intracranial pressure. Therefore, it is crucial to strictly determine the appropriate indications. For patients with cerebral hemorrhage, cerebral embolism, or extensive cerebral infarction, the peak period of cerebral edema generally occurs between five to seven days, during which time mannitol should be used to lower intracranial pressure. If the acute phase has passed, then there is no need to use mannitol. For some patients, using mannitol weeks later not only lacks therapeutic effect, it might even worsen the condition. Additionally, when using mannitol, it is important to monitor the patient's renal function. In patients with renal insufficiency, the use of mannitol may exacerbate renal damage, so monitoring changes in renal function is essential. (Please use medication under the guidance of a doctor.)