Congenital health conditions
Sometimes brain aneurysms arise develop due to health conditions present at birth. These conditions [3] do not always cause a brain aneurysm to develop; they simply increase the likelihood.
Autosomal polycystic kidney disease is an inherited kidney disorder. It causes many fluid-filled sacs (cysts) to form in the kidney. This usually interferes with kidney function and can cause a person’s blood pressure to rise significantly. This increase in blood pressure can cause weak spots to develop in the blood vessels of the brain.
Cerebral arteriovenous malformation (brain AVM) is also an important risk factor. Here the arterial and venous blood vessels in the brain are linked in an abnormal way that interferes with how blood flows in the brain.
Having an unusually narrow aorta, or inherited connective tissue disorders that weaken the blood vessels can also greatly increase your risk of brain aneurysms.