Subarachnoid hemorrhage and cerebral hemorrhage, though both involve bleeding, have different mechanisms of onset. The first distinction is that cerebral hemorrhage is generally caused by hypertension. Hypertension leads to hyaline degeneration and fibrinoid necrosis of arteries, resulting in bleeding. In contrast, the most common cause of subarachnoid hemorrhage is an aneurysm, which may be related to factors such as smoking and congenital developmental abnormalities. In terms of clinical presentation, cerebral hemorrhage has a sudden onset, with symptoms of headache, nausea, vomiting, but also includes impairments in language functions, and signs of neurological deficits such as limb paralysis. Subarachnoid hemorrhage, on the other hand, typically involves very severe pain, usually without manifestations such as limb paralysis. Furthermore, from a radiological perspective on CT imaging, cerebral hemorrhage is mainly located in the brain parenchyma, while subarachnoid hemorrhage mainly indicates that the site of bleeding is in the subarachnoid space.