1. Ischemic stroke: cerebral thrombosis mostly develops in the quiet state or during sleep, and may be preceded by transient ischemic attacks. The first symptoms of the internal carotid artery system are often hemiparesis and decreased hemianesthesia. If the lesion is in the dominant hemisphere, there is aphasia. If the lesion is more extensive, coma is also seen. The first symptoms of the vertebrobasilar system are vertigo, nausea, vomiting, fear of opening the eyes, and in severe cases, tetraplegia and coma. Transient ischemic attack, the above signs and symptoms usually disappear within 24 h. TIA recurs and some patients eventually develop complete stroke. 2. Hemorrhagic stroke: Blood breaks into the brain parenchyma and the intracranial pressure suddenly rises, resulting in a series of symptoms, such as headache, nausea, vomiting, and impaired consciousness. The most common hypertensive cerebral hemorrhage occurs in the basal ganglia and thalamus and spreads to the region of the internal capsule, forming an intracerebral hematoma. Signs and symptoms of cerebral hemorrhage vary depending on the site and size of the hematoma. Most patients have varying degrees of impaired consciousness, ranging from drowsiness to coma. Patient cooperation may also reveal isotropic hemianopia contralateral to the lesion, called the “triple hemianopia” sign of internal capsule hemorrhage. In subarachnoid hemorrhage caused by aneurysm or vascular malformation, there is severe headache, nausea, vomiting, no focal signs, and prominent signs of meningeal irritation, such as cervical tonicity. Electrocardiographic abnormalities are often present in cases of subarachnoid hemorrhage. Some subarachnoid hemorrhages cause vasospasm and focal signs, such as aphasia and hemiparesis. Absorption of cerebrospinal fluid is affected, with hydrocephalus, progressive mental retardation and even dementia.