​Overview

A cerebral (brain) aneurysm is a bulging or ballooning out of a part of a blood vessel wall due to a weak point in the latter’s wall. As the aneurysm grows, the vessel wall becomes thinner and weaker. It can become so thin that it spontaneously leaks or ruptures, releasing blood into the space around the brain called the subarachnoid space. This results in a subarachnoid haemorrhage (SAH). Blood can also leak into the cerebrospinal fluid (brain fluid) or into the brain substance itself, resulting in an intracerebral haematoma (blood clot). This blood can irritate, damage or destroy nearby brain cells. In more serious cases, the bleeding may cause brain damage, paralysis, coma or even death.