Brain aneurysm is also called intracranial aneurysm, although it is called “aneurysm” but it is not a tumor, it is a bulging bag or bubble on the intracranial blood vessels, due to the long-term blood flow impact, the bubble grows and may burst and bleed at the weak place, resulting in cerebral hemorrhage, leading to the so-called subarachnoid hemorrhage, the patient will have a sudden and severe headache, vomiting, etc., and in serious cases, he will die in a coma within a few minutes, because the onset of the disease is more urgent, people often call it an intracranial “intracranial time bomb”, since it is a time bomb, if bleeding has occurred, it may bleed again at any time without surgery or intervention and become dangerous.