Does a brain aneurysm form quickly?

It may form quickly depending on what event. There is a defect in the blood vessel wall is the basis and if there is enough pressure within the vessel it could bulge quickly; but it may also be gradual. The important thing is to be evaluated by competent and experienced physicians that may be able to prevent catastrophe.

Usually, a congenital berry aneurysm slowly enlarges over years to a critical size and potential rupture when critical size is achieved. Aneurysms secondary to uncontrolled hypertension may develop over months and also present clinically with local hemorrhage. Septic or mycotic aneurysms can develop over days if an infection such as bacterial endocarditis is present.