| | Smoking |
| | Hypertension |
| | Congenital resulting from inborn abnormality in artery wall |
| | Drug use, particularly cocaine |
| | Infection |
| | Tumors |
| | Traumatic head injury |
| | Family history of brain aneurysms |
| | Other inherited disorders: Ehler's Syndrome, Polycystic Kidney Disease, and Marfan's Syndrome |
| | Presence of an arteriovenous malformation |