What is a subarachnoid hemorrhage? In simple terms, our brain tissue is covered with a transparent membrane like a spider’s web. The space between this membrane and the brain tissue is called the subarachnoid space, which is normally filled with clear, watery cerebrospinal fluid. The most common cause of subarachnoid hemorrhage is a ruptured aneurysm, which is called an aneurysm, but is essentially a balloon-like expansion of the arterial vessels. We treated nearly 300 cases of aneurysms with spring-ring embolization last year alone, and the majority of patients recovered. Therefore, once subarachnoid hemorrhage occurs, do not panic, but treat the aneurysm in a timely manner, otherwise the aneurysm is prone to rebleeding, and then the chances of survival are very slim. There was an excellent teacher who had a subarachnoid hemorrhage that was clearly an aneurysm, but the patient and his wife, who was also a teacher, were afraid of the risks of surgery and refused to operate, and repeated explanations were ineffective, and he died a month later from another hemorrhage, which was a great pity.