Intracranial Aneurysm

By: CPMC Genetic Counseling Staff
Reviewed by: Larisa Syrow, MD, Rohan Chitale, MD, Cooper University Hospital 

What is an Intracranial Aneurysm?

An intracranial aneurysm, also referred to as a cerebral or brain aneurysm, is a weak spot on a blood vessel in the brain that bulges and fills with blood1. Aneurysms can occur anywhere in the brain, but they are most commonly found in the arteries at the base of the brain. Intracranial aneurysms can occur in individuals of all ages and can be present at birth or developed later in life.

Most intracranial aneurysms do not cause any symptoms and are only detected during medical tests for other conditions.

Intracranial aneurysms alone do not present a health risk. However, if an aneurysm were to rupture resulting in bleeding inside the skull around the brain (hemorrhagic stroke), it can cause serious complications, including permanent disability and possibly death1. All intracranial aneurysms have the potential to rupture; however, most do not. Symptoms of a ruptured aneurysm include: a sudden extremely severe headache (described as "the worst headache of one's life"), decreased consciousness, confusion, nausea and vomiting, stiff neck, and seizures2,3.

How Common are Intracranial Aneurysms?

The prevalence of unruptured intracranial aneurysms has been estimated to be between 1 and 6% of the general population with most aneurysms occurring in adults4. Aneurysms occur more frequently in women and most often appear between the ages of 30-705.

About 1 in 10,000 persons per year will have an aneurysm that ruptures. In the United States, close to 30,000 people will have an intracranial aneurysm rupture each year1,6. The risk of having an aneurysm rupture is higher for women and older individuals. The location, size, and presence of symptoms also contribute to the risk of aneurysm rupture6.

To schedule a free telephone consultation to discuss your CPMC results with a board-certified genetic counselor, email This email address is being protected from spambots. You need JavaScript enabled to view it. .

Learn more about Intracranial Aneurysms, from symptoms to understanding your risk, through the links below.

Page References

2. Vega C, Kwoon JV, Lavine SD. (2002). Intracranial aneurysms: current evidence and clinical practice. Am Fam Physician. 66(4):601-608.
3. Cianfoni A, Pravata E, De Blasi R, Tschuor CS, Bonaldi G. (2013). Clinical presentation of cerebral aneurysms. European journal of radiology. 82(10):1618-22.
4. Komotar RJ, Mocco J, Solomon RA. (2008). Guidelines for the surgical treatment of unruptured intracranial aneurysms: the first annual J. Lawrence pool memorial research symposium – controversies in the management of cerebral aneurysms. Neurosurgery. 62(1):183-193.
5. Vlak MH, Algra A, Brandenburg R, Rinkel GJ. (2011).Prevalence of unruptured intracranial aneurysms, with emphasis on sex, age, comorbidity, country, and time period: a systematic review and meta-analysis. Lancet Neurol. 10(7):626-636.
6. Rinkel GJ, Djibuti M, Algra A, van Gijn J. (1998). Prevalence and risk of rupture of intracranial aneurysms: a systematic review. Stroke. 29(1):251-256.

Symptoms, Diagnosis, Treatment

Learn more about Intracranial Aneurysms Learn More› ]

Risk Factors

Both genetic and non-genetic factors play a role in Intracranial Aneurysms
Learn More› ]

Reduce Your Risk

Risk-reducing behaviors for Intracranial Aneurysm Learn More› ]

The CPMC Study

Learn how the CPMC Study identifies your risk for Intracranial Aneurysm Learn More› ]