With the improvement of living standard and medical technology, intracranial aneurysm is gradually recognized by everyone, that intracranial aneurysm has the word aneurysm, is it a tumor? In fact, intracranial aneurysm is not a tumor as we usually say, it just refers to the expansion on the wall of intracranial arterial blood vessels, which is a thin wall composed of outer and middle membranes, and it is called intracranial aneurysm because the general form is protruding like a balloon, somewhat similar to the appearance of a tumor. What causes intracranial aneurysm? With the continuous improvement of living standard and medical technology, intracranial aneurysm is getting more and more attention. How is an intracranial aneurysm caused? Is there any way to avoid intracranial aneurysm? First of all, according to the current medical level, there is no clear statement on how intracranial aneurysm is caused, and to be direct, it is not very clear. However, there are several factors related to the formation of intracranial aneurysm as follows. 1. Congenital factors: It refers to those formed by birth. According to anatomy, the middle layer of intracranial artery wall lacks elastic fiber and smooth muscle, but the blood flow it has to bear is very large, and there is no corresponding tissue support around it, so the impact it receives at the bifurcation or bend of the blood vessel is very large, if the intracranial artery has congenital abnormal development, then it is easy to develop into aneurysm at the bifurcation or bend of the blood vessel. 2.Blood flow impact: As mentioned in the previous congenital factors, the bifurcation or bend is susceptible to blood flow impact and aneurysm. 3.Arteriosclerosis: Arteriosclerosis is a pathological change that is very likely to occur in middle and old age nowadays. If the artery is hardened, then its arterial wall elastic fibers break and disappear, and it will cause occlusion of the arterial nutrient vessels and make the vessel wall degenerate, thus making the vessel bear more pressure, and this condition will usually form a pike aneurysm. Infection: Infected aneurysms account for about 4% of all aneurysms and are relatively rare. Infections in all parts of the body can take the form of small emboli disseminated through the bloodstream and lodged in the weekend branches of the cerebral arteries, with a few emboli lodged in the bifurcation of the arteries. Infected or fungal aneurysms can also be caused by external erosion of the arterial wall by skull base bone infections, intracranial abscesses, and meningitis. The shape of infected aneurysm is mostly irregular. 5.Trauma: Most of the traumas form pseudoaneurysms, and very few of them also form true aneurysms. From the above analysis, we can see that except for the first and second points which cannot be controlled by human, we can still prevent and control atherosclerosis, infection and trauma to avoid intracranial aneurysm. How to prevent intracranial aneurysm? Intracranial aneurysm is a life-threatening disease if it ruptures and bleeds, so how can we prevent it? The causes of intracranial aneurysms are not well understood according to the current state of medical care, but there are several factors associated with the formation of intracranial aneurysms: congenital development, blood flow shock, infection, atherosclerosis, and trauma, and we can do what we can to reduce the likelihood of intracranial aneurysms. There is no way to control congenital development and blood flow impact, but we can do something about the last three factors mentioned above. Firstly, we should control the occurrence of infections and go to the hospital promptly to prevent the damage of infectious diseases on blood vessels. Secondly, we should pay attention to the occurrence of atherosclerosis and change the existing bad life, such as alcoholism, high fat, staying up late and lack of exercise, etc. Thirdly, we should try to protect ourselves from major trauma, especially head trauma.