A brain (cerebral) aneurysm is a bulging, weak
area in the wall of an artery that supplies blood to the brain. In most cases,
a brain aneurysm causes no symptoms and goes unnoticed. In rare cases, the
brain aneurysm ruptures, releasing blood into the skull and causing a
When a brain aneurysm ruptures,
the result is called a
subarachnoid hemorrhage. Depending on the severity of
the hemorrhage, brain damage or death may result.
The most common
location for brain aneurysms is in the network of blood vessels at the base of
the brain called the circle of Willis.
What causes a brain aneurysm?
A person may inherit the tendency
to form aneurysms, or aneurysms may develop because of hardening of the
arteries (atherosclerosis) and aging. Some risk factors that can
lead to brain aneurysms can be controlled, and others can't. The following risk
factors may increase your risk for an aneurysm or, if you already
have an aneurysm, may increase your risk of it rupturing:
Family history. People
who have a family history of brain aneurysms are more likely to have an
aneurysm than those who don't.
Previous aneurysm. People who have had a brain aneurysm are more likely to have another.
Gender. Women are more likely to
develop a brain aneurysm or to suffer a
Race. African Americans are more likely than whites to have a subarachnoid
High blood pressure. The
risk of subarachnoid hemorrhage is greater in people who have a history of
high blood pressure.
Smoking. In addition to being a cause of high blood pressure, the use
of cigarettes may greatly increase the chances of a brain aneurysm rupturing.
What are the symptoms?
Most brain aneurysms cause no symptoms and may only be discovered during
tests for another, usually unrelated, condition. In other cases, an unruptured
aneurysm will cause problems by pressing on areas in the brain. When this
happens, the person may suffer from severe headaches, blurred vision, changes
in speech, and neck pain, depending on what areas of the brain are affected
and how bad the aneurysm is.
Symptoms of a ruptured brain aneurysm often
come on suddenly. If you have any of the following symptoms or
notice them in someone you know, call 911 or other emergency services right away:
A sudden, severe headache that is
different from past headaches.