The symptoms and signs of cerebral infarction and cerebral hemorrhage vary depending on the location of the brain lesion. The most common ones include motor disorders (limb weakness) and sensory disorders (numbness, dullness, etc.) of the lateral limb or one limb, speech disorders (slurred speech), aphasia (inability to speak, to understand the meaning of words, etc.), balance disorders, trunk incoordination, blurred or double vision, unexplained headache, dizziness, etc. In terms of the development of symptoms after the onset of the disease, the symptoms of atherothrombotic infarction usually do not appear immediately and completely, but mostly deteriorate little by little in stages; cardiogenic cerebral embolism can cause severe symptoms such as hemiplegia or aphasia within seconds; cerebral hemorrhage has a headache and nausea at the onset, with the main symptoms peaking a few minutes to tens of minutes after the onset, and the consciousness gradually deteriorates. In subarachnoid hemorrhage, the onset is characterized by intense headache and vomiting, with symptoms peaking almost immediately and possibly leading to impaired consciousness.