Basilar artery aneurysm may be caused by arterial inflammatory changes, atherosclerosis, and medical injury. 1. Inflammatory changes of arteries: Arteritis, Kawasaki disease, White’s syndrome and other non-bacterial inflammatory diseases of the arteries often involve the basilar artery, and basilar artery aneurysm will be formed. 2. Atherosclerosis: atherosclerosis involving the basilar artery will form basilar artery aneurysm, but also hypertension, coronary heart disease and other parts of the arteriosclerosis of the elderly, can be multiple aneurysms. 3. Medical injury: intracranial surgery such as interventional surgery leads to injury, which may also lead to the formation of basilar aneurysm, and pseudoaneurysm is common. There may be other reasons for basilar aneurysm, and it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment under the guidance of the doctor.