What is the cause of subarachnoid hemorrhage?

Subarachnoid hemorrhage, mostly caused by cerebral vascular malformation, may also be hemangioma, leading to blood flow impact deformity site, leading to abnormal site rupture bleeding phenomenon. Secondly, patients with hypertension, cerebral vascular elastic fiber rupture, there will also be the possibility of bleeding. In addition, when the body mood fluctuations are relatively large, it will also induce subarachnoid hemorrhage.