Since the introduction of CT, the clinical diagnosis of cerebral hemorrhage has not been difficult. 1, the main basis for the diagnosis of cerebral hemorrhage (1) Most of them are over 50 years old, with a longer-term history of hypertensive atherosclerosis. (2) Sudden onset during physical activity or emotional excitement, with symptoms such as headache, vomiting, and impaired consciousness. (3) The onset is rapid, with symptoms of limb dysfunction and increased intracranial pressure within minutes or hours. (4) There are neurological localization signs on physical examination. (5) CT scan examination of the brain: the intracerebral hematoma is a high-density area, and can be accurately displayed for hematomas larger than 1.5 cm in diameter. The site of hemorrhage, the size of the hematoma, whether it has broken into the ventricle, and whether there is cerebral edema and brain hernia formation can be determined. (6) Blood cerebrospinal fluid can be seen in lumbar puncture, but nowadays, cerebral hemorrhage is rarely diagnosed according to cerebrospinal fluid. 2, etiological diagnosis For patients with cerebral hemorrhage, not only the diagnosis of cerebral hemorrhage, but also the etiology must be found to facilitate treatment and prevention. Most causes of cerebral hemorrhage are due to hypertensive atherosclerosis. However, there are many other uncommon causes that can cause cerebral hemorrhage, such as simple atherosclerosis, arteriovenous malformation, hematologic disease, as well as activity status, defecation, emotional agitation, etc. Especially for young adults with onset under 50 years of age, the following etiologies should be considered comprehensively. (1) Rupture of a small arteriovenous malformation or congenital aneurysm in the brain parenchyma. After rupture, a hematoma is formed and the malformed vessel or aneurysm disappears on its own. Even if cerebral angiography is done, it is difficult to show. (2) Periarteritis nodosa, virus, rickettsial infection, etc. can cause arteritis, resulting in wall necrosis and rupture. (3) Vitamin C and B deficiency, necrosis of the endothelium of small blood vessels in the brain, punctate hemorrhage may occur or fuse into a hematoma. (4) Blood diseases: such as leukemia, platelet deficiency purpura, hemophilia, etc. (5) Cerebral hemorrhage may occur during anticoagulation therapy. (6) Intracranial tumor hemorrhage: tumor can erode blood vessels causing cerebral hemorrhage and bleeding from ruptured neovascularization within the tumor. (7) Amyloid angiopathy: mostly seen in the elderly, with recurrent and/or multiple lobar hemorrhages as the main clinical manifestations, with the frontal and parietal cortices being the most obvious. (8) Allergic reactions: can produce punctate hemorrhage in the brain. (9) Dehydration, cerebral venous thrombosis due to sepsis and hyperemesis, etc., can sometimes cause cerebral hemorrhage.