Subarachnoid hemorrhage is a very dangerous disease, in which patients experience severe headaches, noticeable nausea, vomiting, restlessness, and agitation. If the bleeding is extensive, the patient can quickly become comatose and may develop serious complications such as cerebral vasospasm and hydrocephalus. Common causes of cerebral hemorrhage include: First, cerebral aneurysms. Cerebral aneurysms are the most common cause of subarachnoid hemorrhage and may be related to congenital developmental abnormalities or acquired factors such as smoking. Second, arteriovenous malformations, which are also a common cause of bleeding. Third, there are other causes, such as trauma or coagulation disorders, and long-term use of anticoagulant medications may also be contributing factors.