There’s no known way to prevent a brain aneurysm. But you may reduce risk, including treating high blood pressure.

Brain aneurysms, also sometimes referred to as intracranial or cerebral aneurysms, are spots in the brain where weak or thin arteries have bulged out and filled with blood.

Researchers don’t know exactly how common they are, explains the National Health Service. Some experts estimate 1 in 20 people experience a brain aneurysm, while others estimate as few as 1 in 100 experience one.

It’s important to take brain aneurysms seriously because they can cause brain damage or death.

Knowing the serious potential risks associated with brain aneurysms and how frequently they may occur, you’re certainly not alone if you’re wondering how to prevent one.

There is no known way to prevent a brain aneurysm.

However, people can lower their chances of experiencing one by:

  • not smoking cigarettes
  • treating high blood pressure
  • taking steps to address other risk factors

It’s still not entirely clear what causes brain aneurysms.

In some cases, brain aneurysms are associated with weaknesses in the arteries in the brain that are present from birth. This might be due to inherited disorders or a family history of brain aneurysms.

In other cases, blood vessels in the brain weaken with age or lifestyle choices, like smoking.

Weakening blood vessels in the brain can also be associated with health conditions like high blood pressure (hypertension), brain tumors, or atherosclerosis.

Risk factors for a brain aneurysm include:

Brain tumors, head trauma, infection in the artery walls, and atherosclerosis may also increase the chances of a brain aneurysm.

People ages 40 years and older are more at risk of a brain aneurysm, and women are more likely to have a brain aneurysm than men, according to the National Institute of Neurological Disorders and Stroke.

There has been some debate about whether brain aneurysms grow at a predictable rate and how this may correspond with the possibility of a rupture.

In research from 2008, study authors hypothesized that brain aneurysms grow in a way that is “irregular and discontinuous.”

However, a 2009 study presented a mathematical formula that researchers believe links growth rate and rupture rate. Their formula could be used to predict aneurysm growth rate and explains why some aneurysms grow to a certain size without rupture.

Those researchers determined that brain aneurysms often grow rapidly after they first form. However, growth slows between 5 and 8 millimeters (mm). The speed of aneurysm growth seems to increase again after 10 mm.

There have been different scoring methods proposed since those studies, including the PHASES score that explores the 5-year rupture risk. These scoring methods describe how fast a brain aneurysm may grow and how it should be monitored based on that growth.

Technology and diagnostic tools used in detecting a brain aneurysm have also improved through the years. Brain aneurysm can now be found much earlier than before.

If you receive a diagnosis of an unruptured brain aneurysm, your doctor will monitor the size of the aneurysm and try to mitigate any risk factors, like high blood pressure, that may cause it to rupture.

Many brain aneurysms have no symptoms until they rupture or grow in a way that places additional pressure on surrounding brain tissues and nerves.

Symptoms you may experience in these cases include:

  • vision difficulties, such as vision loss and double vision
  • headaches
  • numbness or weakness on one side of the face
  • trouble speaking
  • lack of balance
  • pain around the eyes
  • difficulties with short-term memory and concentration
  • stiffness or pain in the neck
  • nausea and vomiting
  • loss of consciousness or seizures

Factors that impact survival with a brain aneurysm include the size and location of the aneurysm and the amount of hemorrhaging and brain damage.

Some brain aneurysms are small and are at low risk of rupturing or causing symptoms. People who have these types of brain aneurysms may never even know they have one.

If a brain aneurysm does rupture, 25% of people will not survive past 24 hours. Half of people do not survive more than 3 months after a ruptured brain aneurysm.

Because ruptured brain aneurysms can be fatal, it’s important to notify a doctor immediately if you are having any symptoms of a brain aneurysm.

There is no way to prevent brain aneurysms. However, you can decrease the chances you’ll have one with lifestyle strategies, like not smoking and treating high blood pressure.

Ruptured brain aneurysms have a high fatality rate, so it’s important to notify a doctor right away if you do experience symptoms of a brain aneurysm.